I have a Twitter account, but mostly to follow, not to twitter myself. If you were twittering in the beginning, you know what it's all about -- if not, then you likely don't understand the premise.
Twitter started as a way to "status update" followers via text messages from your cell phone (hence the character limit), and in that light, was pretty revolutionary -- if nothing more than simple, though. It pre-dated "smartphones," but was able to adapt beyond text message status updates, I think.
I can see both sides of the fence: why people like it, and, at the same time, why people don't -- or don't understand what all the hype is about.
Conan O'Brian and "Sh** My Dad Says" are too damn funny to pass up; however, the latter seems to have gone mostly silent since the TV show deal. TV ruins everything.