For the most part, Twitter seems to me a sometimes amusing but mostly useless tool. Following people’s tweets gives the impression of being in a large sheep herd with a lot of bleating. Mostly the bleats boil down to “I am here.” However, I’m nevertheless thinking of ways to use Twitter in teaching. It could either be a writing exercise for students (they tweet) or a you-should-always-be-thinking-about-the-course-material tool (I tweet). Either way, unless there’s significant penetration of Twitter among students, I can’t see using it for any all-class assignments. Given my experience with blogs, online forums, etc. asking students to express themselves through an unfamiliar medium is unlikely to have a lasting effect. The trick is to keep it optional but useful enough that students will come to it on their own.