If you ever wonder what the hell is twitter, Eric Ries (in this video), gives an excellent example of how to use it. He gather knowledge about his customers by starting his presentation and telling everybody the only rule is to tweet with hashtag #leanstartup. This is a great way to start a presentation and I know many of you give presentations quite regularly. After he finishes, he search for the #hashtag and see what people are talking. Ask yourself, what is the #hashtag that represents you? Think about that for a while.