What Is Twitter, How It's Most Commonly Used, And Why You Should Be Twittering Right Now (tomuse.com)

To give one answer, I wrote a blog post that I think is interesting about Twitter as a protocol. This is ringing more and more true as new apps are created that use Twitter's tagging structure as a backbone for their app's data structure and communication.

http://www.thinksketchdesign.com/2009/02/25/design/algorithm...