Has anyone else coded up some hot forums?

I looked for a lightweight, easily stylable solution for a while, but I couldn't find any. I'm halfway through a PHP hack (you can register, login, and post threads and replies, just need a profile viewer/editor and a bunch of testing and it should be finished). I don't care much for a PM system when there's an email address/aim/msn/other contact info in the user's profile. It wasn't as hard as I thought it was, but does anyone know an easier method?