The Wired Campus is running a series of articles on using Twitter, the popular micro-blogging platform, as a classroom tool. Here’s the first article (interesting stuff in the comments there), and here’s a followup with a short video from a Twittering professor. And here’s a more lengthy article from Chronicle.com.
Twitter does appear to provide good backchannel discussion opportunities for those who are motivated to use it productively, and as a corollary there are some interesting out-of-classroom student interaction possibilities there. But my experience with any form of online communication is that students like it if they are pushing the information to people of their choosing (such as IM) but not if class stuff is being pushed to them (such as Twitter or even regular email). Control of information is a really big issue with students, and it profoundly creeps them out sometimes when professors presume to include them in backchannel conversations about class.