As many of you know I tweet as @theoverheadwire. Same planning stuff with a bit of personal mish mash. It's interesting to see how we use blogs and twitter differently. As of late, I've stopped posting a lot of my Notes posts and left most of the articles to twitter. Sometimes that's annoying as it doesn't allow much editorializing due to the character limit, but it allows me to do more generally.
In any event, I think twitter can be used effectively. I recently had a phone chat with Kristen Carney (@cubitplanning) about how I got started on Twitter and why I use it. I'll admit, it's not for everyone, but it certainly is useful at finding lots of quality information and news. And no, you don't have to know whats going on with Britney Spears or Ashton Kutcher because you can choose not to follow them!
Also, Kristen has a post about twitter happenings at the APA conference.