There's a great site for Alternity over at
AlternityRPG.net that has forums, resources, articles, stories, etc. There's a
ton of good stuff there if you're into Alternity.
I used to frequent the D&D boards over at the Wizards site, but I tired of the WotC community (and on top of that, I don't really play 3x much, although that may change).
That's all I can think of at the moment.