Are you trying to Twitter with students, I like to, but network filtering has started to become more than a problem of late. So how about a microblogging system that has been designed specifically for teachers and students? If you have not seen it yet, then take a look at Edmodo. In essence similar to Twitter, but with some functionality to support classroom activities. If you sign up as a Teacher, then you can create groups that students can join, then messages, files, links, and even assignments can be sent to the whole group. Students on the other hand can belong to multiple groups. Even better, assignments can be set with hand-in dates due dates, have attachments, uploaded or simply replied to. Having received the assignment, as a teacher you can then provide scoring and feedback. There is even a built-in calendar that shows students their assignment date and grading.

Will this just get filtered also, I guess as it’s a private communication platform built specifically for teachers and students, then maybe not. As you now have what is effectively a significantly enhanced micrblogging facility, removed from the otherwise normal level of noise of other social networks, then it should remain fully accessible, at least that’s the argument I shall be using.
If you would like to know more about Edmodo then I recommend you take a look at their blog, and of course please feel free to reply to this posting if you have any views or experience of what looks could become a very useful and popular product.