Twitter - Why should educators use it?

Twitter - why should we use it? This is a question that I am often asked by teachers as the high school technology facilitator and a teacher.At first I found it a struggle to come up with reasons why a teacher would use this source. However, the more I discuss it the more possibilities I can see. So I thought I would share a couple of great uses from my colleagues at school:Mr Dalesio - Economics - He asks every pupil in class to follow him on twitter and whenever he finds a good article he posts it on twitter. He then encourages pupils to tweet reactions and to write reports on articles that have been tweeted. He also gives the pupils a list of twitter feeds that they should follow and encourages them to find others. In this way economics is a living and breathing thing. It is not just the text book but is real examples that the pupils can follow and engage with. Ultimately this can lead the pupils on a voyage of discovery. However, by giving pupils actual tasks that they need to perform you can ensure that the voyage has some specific goals ..... hopefully they will then go beyond these goalsMr Sugden - Humanities - The pupils will be looking at the French Revolution and how word of mouth and social networking enabled the revolution to develop. Using twitter to show how these same networking skills are used today and looking at how stories and ideas can develop, change, spread through a medium such as twitter draws excellent comparisons and gives the pupils a very tangible reference point.These are only two of the many possible examples I could share and I would be interested in any other uses out there. Twitter is a great resource. My question would be as educators how else could we harness it?