Earlier tonight, Xobni quietly released, at least to some users, a new version of its Outlook plug-in that brings Twitter streams into your email in an intelligent way. Instead of acting like any other Twitter client and showing you the full stream of everyone you follow, it shows you only the recent Tweets of the person whose email you are reading, whether or not you follow them on Twitter. (A Xobni blog post went up briefly about it and then was taken down, but not before I was able to grab the screenshot at right).

Instead of replicating Twitter outright, it shows you the Tweets in the context of an email to help you learn more about the person with whom you are communicating. This is consistent with the way Xobni brings up similar information about a contact from Facebook or LinkedIn or Skype. If you don’t know the person, it gives you some more context. If you do, it gives you something personal to talk about. (Threadsy, which launched at this year’s TC50, also shows Tweets in context alongside emails).

With both the full Facebook stream and now Twitter built into the product, chances are you’ll see what each contact has been doing recently. Xobni also lets you reply via Twitter, and follow a contact from within its application.

One of Xobni’s investors is Vinod Khosla, who told me a few weeks ago that Xobni is getting “great traction.” I’ve since heard that the product is approaching 3 million downloads.