Twitter as a Learning Tool?

Could the free micro-blogging platform Twitter be used to enhance a classroom experience or add value pre or post class? Take a look at these articles which explore the use of Twitter as a learning tool. Could it be used by instructors to keep students informed about coursework, reading materials, and provide a place for discussion? Explore the whys: ASTD, Litmos, Tom Barrett, and Classroom 2.0, Ron Jones. I use Twitter regularly and I believe with the right approach it can be a useful and easy to setup tool for learning. Hey its free! The ability to virtually connect, open up a peer-to-peer network on the fly, easily share links, follow thought leaders, and ask questions and get answers immediately is, lets face it, extremely valuable. The question for me is not why should we use Twitter but why aren't we using it.