I was on the All Games Considered [1] podcast this past Tuesday (the show isn’t out yet), and Mark Kinney, one of the two hosts, mentioned the GM’s Workshop LiveJournal Community [2].
I’m not wild about LJ as a format, but YMMV — and so far, it looks pretty good, with a nice mix of specific and general questions (much like our GMing Q&A Forum [3]) and some solid responses.