I used to post regularly on the old garagepunk forums, but I don't use this hideout as much due to the fact that it gets blocked at work. I also dislike the way the messages are set up--too haphazard and cofusing, and Kopper, if you can get a circa 2002 "old school" looking bulletin board, I'd be more likely to post and participate. It seems like the bulletin board type message board gets past my work's filter. I really miss the old message board...it was a very inviting place.
In terms of other "garage punk" forums out there :I go on the goner records board, but that seems like a smaller, more insular group. The terminal boredom message board is ok, as well...but the musical tastes on that board generally span beyond the garage-punk type music I prefer.