Here's an excerpt
"Twitter is a neat “little” collaboration tool. You could create individual or group Twitter accounts for your students. A class account follows all of the students so we get a live feed of ideas which you can then project using a data projector.
It’s kind of like using classroom clickers (i.e. SMART student response system), but instead of being limited to multiple-choice answers or numerical responses, you’re texting in short messages. In the computer lab, you could ask a question in response to a text (printed or media) and have students respond on Twitter."