Using Twitter to increase motivation in adolescent ESL students

Since starting my new job teaching at a senior high school in September I've been thinking of ways to increase the students' overall motivation to learn English. I would not say that motivation is a problem at my school (thankfully!) but I'm up for anything that might give them that extra bit of interest. Many of my students are avid text messagers so I'm wondering if they might be ripe for an introduction to Twitter. 

Many ESL teachers already use regular blogs as a teaching aid and as a way of connecting with their students. There aren't that many teachers using Twitter at the moment and most of those are using it to connect with other ESL teachers and to post links to their ESL blog or site. (I've recently started following Chris Cotter of Heads Up English and Sean of EFL Geek 3.0 and I'm discovering more all the time.)  I've found all sorts of useful things by browsing ESL teachers' Twitter pages, but there doesn't seem to be much information out there about how ESL learners might be able to use Twitter.  I teach roughly 250 students a week. I think it would be pretty cool if I could get a proportion of them regularly posting tweets to each other in English, either from their phones (not in class!) or from the web. 

At present I have not really decided the best way to introduce Twitter to the students. I think I will do it in stages and gauge the students response as I go along. The first step will be to give them a quick survey about how they use the Internet and mobile phones. Then I will start a group blog so that I can post stuff that we've done in class as well as related material. As part of their homework each week I will ask students to post at least one photo (or link, video, etc.) on a given topic with a few lines of text and to leave a comment on another students' post. 

I am hoping the group blog will generate quite a few conversations on and offline and provide the starting point for a little expedition into Twitterland. Twitter would therefore be an extension of the group blog. Now it may well be that the students will simply not be all that interested in microblogging in English but I guess we won't know that until we give it a try. 

Wish me luck! If anyone has any experience using Twitter, or blogs in general, with adolescent ESL students, please leave a comment or contact me via Twitter/naruwan.