Although I am aware of its popularity, I have to admit that I don't use or even understand Twitter. I just read an excellent article about how it started out, how it was initially meant to be used, and how it's used now.
There is a lot of good stuff here about understanding the flow of information (even if it's 140-character "tweets"), and utilizing the information. Interestingly, companies like Starbucks and Dell monitor Twitter to improve their products or refute rumors.
http://www.nytimes.com/2009/04/14/technology/internet/14twitter.html?_r=1&ref=technology
Compared with antiquated pre-internet information flow, Twitter seems like telepathy.