Um, oh hey guys, what’s up? Nothing much over on my side, except that I’d really like a Diet Coke. Also, I’m hearing that nascent photo sharing app née blogging platform Posterous is raising some money. So yeah that’s what’s up over here in my neck of TC HQ.

Chew on this if you’re in the mood for some actual tech news; the simple blogging service and Tumblr competitor has just raised $5 million in Series B according to multiple sources. Taking part in the round will be Redpoint Ventures, newcomer Jafco Ventures and existing angels.

On Monday Posterous revamped its entire product and focus around Posterous Spaces, which — in the same vein as Google Circles — allows users to pick and choose whom they share specific content with. Thus far the product has received mixed response from users.

I’m just going to assume that Posterous will be using the cash to increase its engineering team, because that’s what I usually write every day in these things. This new funding comes in addition to another $5.14 million in seed, angel and Series A financing from Y Combinator, SV Angel, Lowercase Capital, Brian Pokorny and others, making the company’s total funding to date $10.14 million.

I think I just might go get that Diet Coke now.

All users who want to create a Posterous site around an event have to do is open up their iPhones and create a .posterous address for a specific location and post (the site you most recently posted to will stay on top of your events).

Posterous is incorporating SimpleGeo location data into the app, so that anyone with the Posterous iPhone app also in the vicinity of a given event will be able to see that event and post photos and media which are then presented on the site in slideshow format (above).

Says head of marketing Rich Pearson, “Our aim is to make Posterous Events the default place to share at concerts, weddings, parties and conferences – that said, it’s an early version.” Posterous is also planning event notification, private event capability in a later build, but for now, enjoy SXSW Posterousers.

You can find the app in the app store here.

Posterous marketing manager Rich Pearson tells me that Posterous’ mobile efforts have more than doubled its userbase since its launch in December. Group sharing seems to be all the rage and this is Posterous’ most ambitious Group sharing endeavor yet.

Indeed, its newest Android and App build is sort of like a Group-texting app with a website attached, the ideal use case being people who need to quickly share media like photos and videos with  friends, family or coworkers and want to have some sort of easy accessible and lasting web record, which photo-sharing services like Instagram and Group messaging apps like GroupMe currently lack.

Those who want to create a new group in Posterous 2.0 can, go to “Groups” and hit “New Group,” choose a group name and address. You can also conveniently add group members from your phone contacts. Subsequently, you create posts and can upload as many videos or photos as you’d like to the group, all in one fell scoop.

The app, which now supports landscape mode, allows all group members interact with each other’s posts on mobile –You can heart and make comments on individual posts via the app. By default the app emails the other group members of activity when there are new posts and comments.

Posterous, who recently landed a deal with The Gap to power its blog, is planning to add even more functionality with regards to Groups and hopes to launch Posterous Events, which builds Groups around events, right before SXSW.

You can download the app in the iTunes store here, or by searching for “Posterous” in the Android market.

Posterous isn’t taking off as quickly as its competitor Tumblr, but it has a solid audience and has recently released a neat Groups feature. Tan didn’t elaborate much on his reasons for leaving, but says that it boils down to wanting to work with smaller teams, which he’ll be able to do at Y Combinator (Posterous is now at around 13 employees). He also added that Posterous is going “gangbusters” and that he expects 2011 to be “really phenomenal”.

Posterous has raised over $5 million, including Y Combinator funding and a Series A round in March 2010.

Here’s Tan’s post announcing the news on his Posterous blog:

Just as Posterous has prospered, grown and changed, so to is it time for me to evolve my role. Effective today, I’m ending my day-to-day development with Posterous and moving into an advisory role. Though my day-to-day may change, my faith in the team and the product is unchanged and unwavering. Posterous is in good hands and on the right track to fulfilling its potential. I am proud of what we’ve built together and look forward to the future with anticipation to see where the team and you, the users, take this very special community.

My greatest passions lie with the early stage of building world-changing consumer products. To that end, I’ve decided to join the team at Y Combinator as a designer-in-residence and help the dozens of top pre-seed startups in the newest Winter 2011 batch reach their potential through excellent user experience.

I am greatly thankful to our team, investors and most of all our users for all the amazing work and adventures. Thanks for all of your support.

Uptime monitoring service Pingdom has tested five major blogging services for their reliability. Unsurprisingly given its recent woes, micro-blogging startup Tumblr received a disastrous score, while Google’s Blogger came up on top with not a second of downtime.

Pingdom’s tests were performed once a minute over a period of two months, from October 15 to December 15, from multiple locations in both North America and Europe. Included in the tests were Blogger, WordPress.com, Typepad, Tumblr and Posterous. Not only the uptime of the blogging platform’s homepage was monitored, but also four individual blogs.

Pingdom found that Blogger didn’t seem to display any downtime whatsoever in the two months of testing, while WordPress.com also showed an ability to remain available most of the time. Typepad came up third, but not with a lot of difference from the two former blogging service.

When you look at the upstart, basic blogging services, the differences become more clear. Posterous showed mixed results in terms of reliability, but Tumblr clearly takes the downtime cake on that level.

According to Pingdom, some of the Tumblr blogs it monitored during the two-month window were unavailable for more than two days, beating the general downtime of the platform of 24+ hours Tumblr struggled with last week.

Clearly, the startup can use the recent capital injection to improve reliability quite a bit:

However, it should be noted that Tumblr’s problems haven’t just been a few big outages, but a large number of smaller ones. The Tumblr blogs we monitored had an average of more than 300 outages during these two months, some very brief, indicating an ongoing performance issue with the service.

Simple blogging platform Posterous has always been about email and co-founders Sachin Agarwal and Garry Tan have taken the idea of an email list one step further and developed Posterous Groups. Groups, an easier way to hold group discussion, hops on Mark Zuckerberg’s social bus and proves that its only a matter of time before all blogging platforms become even more social. “This came out of our frustration with Yahoo Groups and Google Groups” said Posterous Marketing Manager Rich Pearson, explaining the company’s attempts to develop “the best email list groups product possible.”

Like all things Posterous, the execution is simple. To set up a group simply send an email to “group@posterous.com” with the group name as the subject line and the rest is done by Posterous. To post to the group, send an email to “post@groupname.posterous.com.” The best part is you don’t actually need a Posterous account to be part of a group.

Once in a group, participants have a two column view, where they can experience threaded conversations and upload media attachments. The group moderator can choose whether people are contributors or subscribers and whether the group is public or private. Again the simplicity of Posterous is evident here, as the Groups function is filled with nifty tricks like being able to post a YouTube URL and have it turn into an inline video. Autopost social sharing on services like Facebook, Twitter, Flickr and YouTube is also available on Groups.

Pearson and Agarwal have been beta-testing the product with 1200 users for about a week and the feedback has been mostly positive, with one user calling it, “Blogging meets discussion forums meets commenting.” As Pearson points out, the ideal use case is people who are still in college (“Anyone who is in school is just a part of a ton of email lists”) so it might be prudent to have deeper email and chat integration in a further iteration.

Posterous, which is currently funded at $5.14 million, is also launching their extremely simple mobile app in the Android Marketplace today. The app includes features like social auto-posting, geo-tagging and options to take and upload video and photo. You can find the app in the Android marketplace by searching for “Posterous.”

While you might be experiencing iPhone share fatigue (Instagram, Twitter, Tumblrette, WordPress and many others allow you to upload content directly from your phone) Posterous has always modeled itself on providing its pretty fanatical userbase with ease of use, the original idea of the service being that you could send an email to post@posterous.com and get a blog back, to which you the could send any other subsequent posts to post@sitename.posterous.com.

The Posterous mobile app takes off on this basic “no need to log in” philosophy, but supports geolocational tags, category tags and various levels of editing and privacy. And despite being buggy at points (one of my test posts posted twice, which was confusing), it’s pretty impressive how much you can actually do from the app (for example I set up my whole Posterous account) as opposed to WordPress, which has the effect of making you feel immobilized when blogging on the go because it does not allow you to upload media other than photos and lacks social sharing functions.

Winning “Keep It Simple Stupid” product strategy aside, it’s really hard not to root for the YC-backed Posterous; Their recent skuffle with Twitpic solidified them as champions of user portability which is always a crowd pleaser. Their user traffic has also risen accordingly boasting a 40% increase since June.

Currently funded at $5.14 million, Posterous’ future plans for the iPhone app include building the ability to directly edit posts from the app, landscape post viewing, multiple photo selection and showing attachments as actual thumbnails.

Posterous users can automatically push content posted to their blogs onto other platforms, such as Facebook, Twitter, LinkedIn, Flickr and so on. Up until recently, people could even post content like text, pictures and videos to their Posterous account and subsequently have it auto-posted to a Tumblr blog.

Now, as of this morning it seems, people who try to link a Tumblr blog to the Posterous service in the latter’s back-end get served the following notice, which leaves little to the imagination (emphasis ours):

Link Your Tumblr Account

Your full blog post will get autoposted to your Tumblr. Don’t worry about where you’re going to host your images, files, or music anymore. We’ll always just do the right thing.

Tumblr autopost has been temporarily disabled — seems like they are blocking our API requests at present moment. We’re working on getting this resolved. In the meantime, you might try emailing Tumblr support about it.

In other words, Posterous says Tumblr no longer wishes to host content automatically pushed from Posterous to them, and has thus technically disabled users from autoposting their content. And Posterous is telling users it is investigating the issue and “working on getting this resolved” which means they’re either talking to Tumblr or hacking a workaround.

It’s always possible Tumblr isn’t intentionally blocking API requests from Posterous and that there’s a technical issue that Tumblr will resolve. It also appears Tumblr has opted not to block Posterous’ import tool, which enables people to make the switch to the latter easier.

Update: and indeed, Tumblr CEO David Karp tells me that Posterous hasn’t been blacklisted at all, and that it’s probably just a case of them hitting Tumblr’s normal API throttling, which he adds recently became more aggressive in cases where clients make repeat requests with bad login credentials.

Karp also points out that they’re happy to help sort this out and currently looking into it.

Either way, there’s clearly been a feud growing between the two companies, both backed by venture capital firms, as of late. Both operate in the same, effortless-blogging platform space, and Tumblr is the bigger one and growing faster, but it has also been around for longer and definitely feeling the Posterous heat.

Last June, Posterous embarked on an aggressive switching campaign to attract more users, and one of the companies they singled out was of course Tumblr. Their message back then:

Tumblr is a pretty cool service. They offer easy set up, loads of funky themes and super-simple reblogging. But blogging on Tumblr is sort of like being in high school. But you know deep-down that you can’t be in high school forever. Eventually, you have to move on.

Unlike TwitPic, Tumblr at the time didn’t respond to the campaign by threatening legal action, nor did they block the Posterous auto-post feature as far as we know. It would have made more sense then than it does now, but here we are.

Posterous nor Tumblr has responded to a request for comment so far, but we’ll update if and when they do (update: see above for comment from Tumblr).

Pulse is teaming up with Posterous to create a simple way for users to create their own “Pulses.” What this means is that they can with one tap add any article to their own Pulse — thus making any user an aggregator of news. Posterous comes in because each of these Pulse items are transfered to a free blog which is automatically created for you. “This blog will post the articles you have picked, hence enabling you to share this even with friends who don’t have Pulse,” Alphonso Labs co-founder Akshay Kothari says.

But if your friends are using Pulse, there will be an easy way for them to subscribe to your Pulses, simply by searching for their name or username.

But the most interesting aspect of all of this may be the aggregator Alphonso Labs has created to show off the best of these Pulses: Pulsememe. It’s sort of like Techmeme (though it covers all news, not just tech news), but it relies on these Posterous-powered Pulse blogs to aggregate what’s hot. In a way, it’s actually more like Delicious or Google Reader shared items.

Pulsememe also features a sidebar list of top editors to show off who is discovering the most interesting content.

The service is pretty bare-bones at the moment — but there’s also no one really using it outside of Alphonso Labs employees. If a lot of people get into this idea of using the Pulse app as their own aggregation tool, this could be an interesting way to discover news.

Posterous, meanwhile, continues to come up with interesting ways to get people to create blogs on their network.

Last week, Pulse launched its app on the Android platform. The app also works on the iPhone and iPod touch — though this aggregator tool is only on the iPad app for the time being.

You can find the Pulse app here. It’s $3.99.

Here’s the press release about Snapfish’s acquisition of Motionbox:

Snapfish by HP Acquires Video Platform Technology from Motionbox, Inc.

PALO ALTO, Calif., July 12, 2010 – Snapfish by HP today announced an agreement to acquire the video technology platform from Motionbox, Inc., the video sharing site with over 2.8 million members worldwide. This acquisition will enable Snapfish to expand its online video offering.

“Video is a critical component of digital memory sharing today, and Motionbox’s technology will enable our Snapfish customers to create great personal video memories,” said Helen Vaid, General Manager of Snapfish. “With today’s announcement, we are very excited to start integrating the video platform Motionbox has developed into our popular Snapfish Home Video product.”

Motionbox customers will now be able to experience a seamless photo and video sharing experience as their digital assets will be in one place when they set up their Snapfish account.

“We think Snapfish’s integration of the technology acquired from Motionbox will be a great way to take personal video sharing to the next level”, said Josh Grotstein, CEO of Motionbox and an early backer of the Company. “Our vision has always been to make sharing personal videos as easy and affordable as sharing digital photos. No other photo sharing company is nearly as well positioned to bring our platform to a wide, global market.”

Snapfish by HP is the No. 1 online personal publishing service in the world, with more than more than 85 million registered users in 22 countries and more than 10 billion unique photos stored online. The current Motionbox.com site will continue operating until August 10, 2010.

Somewhere in between full blogging platforms like WordPress and the 140-character limit of Twitter, true microblogging sites like Tumblr and Posterous are taking off. I call these true microblogging sites because they are designed for quick hits but can support photos, themes, and other more blog-like features. Tumblr has been around longer and is getting quite big (23 million monthly unique global visitors, according to Quantcast) , but the younger Posterous is also seeing some decent growth.

According to Quantcast, Posterous has 5.3 million monthly unique global visitors, with 2.2 million in the U.S. (Both Posterous and Tumblr are directly measured by Quantcast). If you look at the Quantcast chart above, you can see the different growth spurts Posterous has gone through. The first year after its launch in June, 2008, it’s growth was pretty gradual. But then, almost a year ago, it introduced an iPhone app which allows users to post their photos and thoughts directly to their Posterous blogs. One of the main uses of Posterous is to share photos with some commentary.

Then earlier this year it started integrating more tightly with Twitter through its Post.ly service, and kept steadily adding new features throughout the year.

Currently the company is trying to fuel growth through a switching campaign targeted at 15 competing services such as Ning and Twitpic, which is getting it in some hot water.

Even taking the more conservative estimates from comScore, which shows Posterous with only 2.5 million worldwide unique visitors in May, 2010, the site is up 700 percent since comScore started collecting data 11 months prior. It is safe to assume that the annual growth is north of 700 percent. Tumblr, by comparison, is up 174 percent during the same period (off a much larger base of users, which comScore estimates 10.7 million worldwide unques in May, 2010). Both are growing spectacularly because when you lower the barriers to publishing, the posts (and audience) will follow.

As you may have read yesterday, TwitPic and Posterous are currently in a row after the latter introduced a “Rescue your photos from TwitPic” tool that provides users with a one-click way to import TwitPic photos over to their Posterous blog.

TwitPic isn’t into the idea and reportedly sent the Posterous team a letter last week threatening legal action against the company if they launched it.

Posterous co-founder Sachin Agarwal told us TwitPic’s claims are bogus, and that “Posterous is simply acting as an agent to the user who owns the photos”. TwitPic for its part seems most concerned about Posterous’ methods for accessing data.

But maybe lawyers won’t be necessary, after all. Check out this tweet from Agarwal, sent to TwitPic founder Noah Everett about half an hour ago (via @cdixon):

“Hey @noaheverett: if you’d like to discuss data portability, please email me. sachin@posterous.com. Lawyers are expensive. We can be friends”

Wouldn’t it be swell if an actual lawsuit was diverted thanks to that tweet?

Are you watching this, @HTC, @Nokia and @ceoSteveJobs (yes, I know it’s a fake)?

Well that didn’t take long. Halfway into their big 15 importers in 15 days campaign, Posterous has managed to make one of their competitors very angry. Twitpic is so angry, in fact, that they’re blocking the service and threatening legal action.

This morning, Posterous introduced their new “Rescue your photos from TwitPic” tool — a one-click way to import your photos from Twitpic over to your Posterous blog. This is the same type of importer Posterous has already made for Ning, Vox, Tumblr and a host of other services — as I said, they’re about halfway through the 15 of these tools they intend to make.

The idea, of course, is that if they make it easy enough to get your existing content on to Posterous, they think you’ll like their service so much that you’ll permanently switch. Twitpic, doesn’t like that idea one bit.

According to Posterous, Twitpic had some idea such a tool might be coming and sent a letter last Thursday threatening to sue the company if they launched it. “Their claims are completely bogus,” Posterous co-founder Sachin Agarwal tells us. “Posterous is simply acting as an agent to the user who owns the photos. We authenticate the user’s Twitter credentials and then download the images on their behalf,” he continues.

“Our lawyer sent a response to TwitPic this morning indicating that we aren’t breaking any laws here, but simply giving users a way to access their own photos and then decide which service they like best. Nevertheless, TwitPic banned our servers within a couple hours of the importer launch,” Agarwal says.

Twitpic has since responded to that letter from Posterous. We’ve had a chance to see them all. Twitpic seems most concerned about Posterous’ methods for accessing this data. The user privacy issue is brought up a number of times — and they also wonder if Posterous isn’t access Twitpic “trade secrets” with this importer.

“We are simply using their public RSS feed to pull images on the user’s behalf. There are no privacy violations here,” Agarwal says.

Twitpic says they’re not going to stop users from exporting their data, but prefer users do so manually, rather than with the use of this tool. Of course, if this really is just pulling the pictures through users’ RSS feeds, it’s hard to argue that this tool is anymore more than useful for people who are looking to switch. Plenty of other blogging sites offer similar import tools.

We’re big fans of easy-to-use blogging platform Posterous, which has seen fast growth, revenue and impressive funding since its launch in 2008. Over the past six months Posterous has steadily added nearly a dozen innovative features to its publishing platform, including static page support, comment moderation, custom domains, and a media sharing service for Twitter. And it’s no secret that Posterous is hoping to be the go-to simple everyday posting platform for consumers. Today, in its quest for world domination, the startup is unveiling a massive switching initiative to help users transfer all content from other posting and blogging sites over to Posterous.

For the next 15 days, Posterous will announce a different service daily that will allow you to transfer your account, blog, videos, images and more over to the simple blogging site for free. First up: Ning. To switch, you simple give Posterous the URL of the Ning blog you want to move and your email address and Posterous will send you an email when they are done copying a site. You don’t have to have a pre-existing account with Posterous either to make the switch.

The switch over times will vary based upon size of site that is being converted, says co-founder Sachin Agarwal. Ten posts will only take a few minutes, but 1000 posts and large amounts of video and images (which Posterous will host) will take longer. The best part is that all of this work is done for you for free. And in case you don’t buy Posterous’ claims, here’s a testimonial page of beta users who have used the importing tools.

As for the platforms that Posterous will now offer switching from, Ning makes sense considering that many Ning owners who were using the network for free may be looking to switch after Ning shuttered its free service. Posterous is a nice alternative, with its enhanced customization features.

So which service is next in the switching plan? Agarwal and VP of Marketing Rich Pearson wouldn’t tell me but I think it’s safe to assume some of the platform that Posterous will target. While Posterous unveiled a “quick and dirty” converter for WordPress last year, Agarwal says it was fairly simple. It’s safe to assume that the startup will be launching a more comprehensive migration tool in the next two weeks. And it’s also safe to assume that TwitPic, Google’s Blogger, TypePad and Tumblr are also included in the lineup.

For Posterous, this is certainly an impressive campaign. Agarwal and Pearson say that this has been something the team has been working on for months. Clearly, Posterous has ambitions of becoming the defacto posting platform and is now making it significantly easier for users to switch. While the company doesn’t reveal number on how many blogs it hosts, Pearson saud that the site is growing in userbase by 20 to 25 percent each month. A little aggressive marketing could speed that growth up significantly.

Of course, other blogging platforms like WordPress have offered this forever, which is one reason why this is important — it’s one less feature users have to sacrifice if they want to trade in the more complex traditional blogging platforms in favor of Posterous’s cleaner interface and simple email-to-post functionality.

Pages are created using the site’s web interface. They can redirect to a static URL, and you can set a Page to be the default landing page when people vist your site (in other words, you could make your About Me section the first thing people see, rather than your blog posts).

Co-founder Sachin Agarwal agrees — in a phone interview he conceded that Posterous should definitely have informed users about the change (they’re currently drafting a statement about the incident). Agarwal says that Posterous has actually been testing the VigLink integration for months, which means the links have gone unnoticed for quite a while. But he says it’s just an experiment, and that Posterous hasn’t decided if it’s going to be keeping them in the long-term (though he agrees they should have informed users regardless).

Agarwal also says that if Posterous does wind up permanently integrating VigLink, users won’t have to take part in the program. And there’s an upside: once they’ve built the infrastructure to support it, Posterous has plans to allow its users to generate revenue from links on their own blogs, which could actually drive more people to start using the publishing platform.

It’s worth pointing out that while VigLink will convert any normal links to affiliate links whenever possible, it will ignore any links that are already connected to affiliate programs (in other words, it doesn’t overwrite existing affiliate links).

Earlier this month, Tumblr rolled out its first attempt at making money: a small ($9) fee to make your blog featured in a directory of blogs. Tomorrow, the service is officially rolling out its second revenue generator: premium themes.

The initial 13 themes being featured in this roll-out look pretty great. They come from 7 different designers and will range in price from $9 all the way up to $49. Tumblr declined to give the revenue split between the company and the designers but says that “most” of the money will go to the designers. The premium themes page is actually already live here.

This seems like a smart play for Tumblr. One thing that separates it from rivals such as Posterous is the attention to design. Tumblr already features over 350 free templates that any user can install with the click of a button. “There’s already been a ton of demand for this platform [premium designs] from our developer community, and we know it will add a spectacular collection of new themes and options for our bloggers,” says founder David Karp.

The roll out of this second premium feature is the latest in a huge amount of updates the service has unveiled in the past several weeks. Those include the ability to add static pages to Tumblr blogs, photo replies, video uploads, and even comments (sort of).

Tumblr is also just about to hit 4 million users.

San Francisco based Posterous, a fast growing publishing platform, has taken a $4.4 million investment from Redpoint Ventures. Partner Satish Dharmaraj, who is also an individual investor in Posterous, led the round and joins the company’s board of directors (and he maintains his personal blog at Posterous here).

Posterous, founded in 2008 by Sachin Agarwal, Garry Tan and Brett Gibson, is a Y Combinator company that began as a way for users to very easily post pictures online. Its appeal lies in its simplicity – users can just email a photo to post@posterous.com and an account is immediately created for them. But today people are using Posterous for videos and text blogs as well. Users can change the CSS and even use their own domain names – see Guy Kawasaki’s HolKaw blog, for example, which is run by Posterous.

The company does have revenue, such as this early deal with Coca Cola for a branded site, but has stood firm in keeping the “nickel and dime” consumer fees out of the product. There are no restrictions on usage, storage, CSS customization or using your own domain, says the company.

Later this year Posterous will launch a pro version of the service for bigger brands, and allow things like Javascript and site monetization for a fee, they say.

All that simplicity and freeness has resulted in a lot of growth for the company. They have 12 million unique monthly visitors, they say, and 25 million page views. And they grew 30% per month in 2009, all with just 4 employees (they are up to 6 now).

Posterous regularly releases new products, such as Post.ly a month ago. Post.ly lets users easily share media on their Twitter account.

CEO Sachin Agarwal says that they want to continue to add new products that make it dead simple to post and share content online: “Our goal is to become synonymous with “posting” just like Google is synonymous with “search”. Doesn’t matter if it’s for twitter or a blog, private or public, group or individual. if you need it online, you go to Posterous.”

Social sharing is becoming a big contributor to traffic for many sites. While Facebook and Twitter drive more sharing than any other services, Google is trying to compete with Buzz, which is now part of Gmail but shares links to article and blog posts through Google Reader. Over the past month, according to AddThis, sharing through Google Reader is up 35 percent, with a big jump on February 9, the day Buzz launched.  This number only measures sharing through the AddThis button, which is on more than 600,000 Websites and gives you the option to share content through more than 200 services. So it is only a proxy for total sharing on Google Reader, but a decent one.

Google Reader still barely registers when compared to Twitter and Facebook, which account for 31 percent and 8 percent of all sharing via AddThis, respectively.  But Buzz is definitely giving it a boost.

You can now chart how different services do against each other on the sharing front via a new services directory on AddThis. For instance, Google Bookmarks does much better than Google Reader, with 5 percent of all AddThis activity.  It even beats Digg (which has 3 percent).  Google Bookmarks is probably used more for personal bookmarking than for social consumption, but it is smack in the middle of Twitter and Digg when it comes to activity via AddThis.

Another comparison is Tumblr versus Posterous, which suggests that Tumblr  is much more popular as a reposting tool, and is about neck-and-neck with WordPress.

Dead-simple blogging and content distribution service Posterous has long used the URL post.ly as a custom branded Web address for blog posts hosted on its platform. Today, the startup is announcing that it has turned Post.ly into a destination site of its own, more specifically making it the latest media sharing service for Twitter.

Staying true to its well-earned reputation of keeping its services as simple as they are functional, Posterous has turned Post.ly into something I can see myself using a lot going forward.

If you’re a Posterous user and logged on, Post.ly will recognize you as such, or you can simply sign in with your username and password. You can then use the tool to send out a tweet to your Twitter account (which you can link up using the OAuth protocol) and add multiple media files like photos, videos, music, documents and more to your message.

If 140 characters doesn’t quite cut it for you, there’s an option to include an unlimited amount of extra text. Evidently, whatever you choose to publish will end up on on your Posterous blog and be distributed to your Twitter stream using Posterous’ auto-post technology.

If you’re not a Posterous user yet, using Post.ly will work in the same fashion as sending an e-mail to post@posterous.com for the first time: it will automatically set up a custom blog for you with your Twitter username, and you can later dive into the settings to configure the title, theme, etc. Couldn’t be easier.

Posterous is introducing this new feature / service because it hopes Post.ly will introduce more people to their core service and entice them to discover more about what it’s capable of. As a Posterous user myself, I think it is also terribly useful for existing users, mainly because for whatever reason you currently can’t upload files to Posterous when you’re publishing a new blog post from the Web.