Tungle, a scheduling and calendar sharing tool, is adding its first premium, paid feature today—branded channels. Tungle.me, which we’ve previously written about here, offers users a free web-based application that lets you share calendars across companies and platforms, schedule meetings with individuals or groups inside or outside their company and propose multiple meeting times in invitations. The service currently syncs with a number of calendar applications, including Outlook, Google Calendar, and Apple iCal.

Users now have the option of upgrading to a premium account to receive the ability to brand public pages and email invitations with their logo and corporate colors, as well as input up to 10 suggested locations in their meeting invitations.

This is the first paid offering for the startup; Tungle.me has been completely free for users. The Personalization feature is $4.99 a month, or $49.99 per year. The company says it will continue to add more premium features but will keep the basic application free.

Since Tungle’s launch in 2009, the company’s scheduling offering is now being used at 800 Universities around the world, by 40% of Fortune 1000 companies, and users from over 150 countries.

Checkout Tungle’s manifesto on the “calendar of the future” here.

Syncing calendars and scheduling meetings over email can be an arduous and annoying task. I’ve often wished that I could just send my calendar to contacts instead of going back and forth over email, so we could find a mutual time that works best for various schedules more quickly. Tungle, a scheduling and calendar sharing tool we wrote about during its launch last year, has made scheduling a meeting a whole lot more social and simple through its Tungle.Me technology.

Tungle offers users Tungle Accelerate, a free web-based application that lets you share calendars across companies and platforms, schedule meetings with individuals or groups inside or outside their company and propose multiple meeting times in invitations. The service currently syncs with Outlook, Google Calendar, Apple iCal, Entourage for Mac, and soon Lotus Notes.

Tungle’s latest technology, Tungle.Me, a “click to meet” application that is integrated with Tungle Accelerate, makes inbound scheduling more social. Once you create a Tungle account, you can also create a Tungle.me URL (you can include this link in an email or message and anyone can click on it) which you can send to contacts. At that site, contacts will input their name and email to verify their identity, then choose an available time to meet with you. Your calendar (which is synced via Tungle) will appear so that contacts can choose an open time. The spots where you have meetings are blocked off. Once a contact requests a meeting, you are sent an email with potential times for meetings. You can accept the meeting time (your calendar will be updated upon approval), send the contact another meeting time or you can deny the meeting all together. If you add meetings into your calendar that are synced with Tungle, your Tungle.me link is updated in real-time. And contacts who request a meeting don’t have to be Tungle users to use the Tungle.me interface.

Your Tungle.me link can also be embedded as a widget in an email or on a site as well as added as a Facebook widget on your profile. The widgets display a real-time glance of a users’ availability and a quick link to their personal Tungle.me URL.

The widget is a great idea, but I’m not so sure I’d want to give Facebook users and all of my friends the ability schedule a meeting with me. There is also the potential for random people, who you don’t know, to spam your email with meeting requests. Of course, you can always deny these meetings but it’s still annoying to sort though random emails in the first place.

But the service itself is a innovative idea and could save users, especially those who have frequent daily and weekly meetings but don’t have a personal assistant or secretary, a lot of time when it comes to scheduling those meetings. And the ability for your Tungle calendar to be synced with Outlook, Google Calendar and other popular scheduling applications makes the service compelling. Tungle’s main competitors are TimeBridge, which also lets you publish your calendar to selected users, and Jiffle.

Meeting coordination service Timebridge now has serious competition from Tungle, a Montreal-based service that opens up into public beta today.

When I met with Tungle CEO Marc Gringas this past January, he outlined the type of technology that would address the major pain points of scheduling meetings: it would reduce the number of transactions needed to pick a time, it would be simple to use across time zones, it would be an open system for anyone to use, and people would be able to see each others’ schedules with it.

Tungle does a good job fulfilling most of these principles. It comes as an Outlook plugin that automatically loads all of your contacts and calendar events (either from Outlook itself or other calendar apps like Google Calendar). You can choose to share your schedule with others who also have the plugin installed, and you can invite others to a meeting whether or not they even use Outlook.

The invitation system is key. Tungle users can invite non-Tungle users by sending them a link to a special coordination page. This “Tungle Space” page shows your availability and solicits their input for when they are also available. If your schedule changes after sending out the invitation, the Tungle Space page will update itself accordingly. And you can use it to invite multiple people to the same meeting. As people visit the page and indicate when they are available, the options get narrowed down until the last invitee to respond chooses a time.

There are many similarities between Tungle and TimeBridge (see our review of the latter here) but Gringas stresses that TimeBridge has more of a “wish list” approach to it, where organizers suggest a set of times and these get either accepted or rejected by invitees. But while Tungle may be more about finding the overlapping free time in participants’ schedules, it lacks the freedom of TimeBridge, which can be used entirely through the browser.

When it comes down to it, this type of product will mostly appeal to a certain class of professionals that needs to schedule group meetings all the time. Many of us only schedule one-on-one meetings that take at most a few emails to pin down, and we won’t be bothered to change our habits. But I imagine there are many assistants and managers out there who will find this very helpful and worth the effort of picking it up.

Tungle raised $1.5M CAD from JLA Ventures and Des Jardins Venture Capital in May 2007. Jiffle is another competitor we covered just last week.