I'm qwyneth on twitter, and ishaa is, well, ishaa. We use it for little tidbits every so often, usually funny things or frustrations. I really enjoy following Dooce's twitter. One of my friends and I keep up on each other's lives more closely through Twitter than we could otherwise, since we live in different areas and don't often get the chance to chat on the phone all that much. Twitter's not necessarily for everyone, but I enjoy it.

Edited to add: And, fortunately, if you don't want to use it or follow specific people, you don't have to! :)