Today's education places a strong emphasis on group work, and rightly so. Students develop invaluable critical skills by listening to a variety of ideas and perspectives while developing their own thoughts. Twitter is a means of continually sharing ideas from a myriad of perspectives.
Teachers and students alike can instantaneously connect with an expert in any field. It took me only a few minutes to find and share ideas with a number of experts in the field of education and technology. The ease of connecting with experts is remarkable.
My students are beginning to moan when I say the word "reflection." But, reflecting is a necessary component of learning. Twittering is a means in which students can reflect upon school activities and what they've learned. If students are asked to twitter about school activities, they'll be participating in self-reflection (without the moaning).
4) Feedback and Idea Development
Twitter is an excellent forum for getting instant feedback on ideas. I teach at a school where the same students are together for years. Sharing and developing ideas through twitter helps my students gain new perspectives and fresh constructive criticism.
Most twitterers, especially the better mindcasters, are continuously posting weblinks. The internet is a big place and some great resources can get buried in google. Twitter helps users connect with a variety of new, thought-provoking, and useful resources. Teachers can continually be learning about new developments and resources in their field.
You can set up an account at Twitter