One of my blog entries [from February 14, 2003!] has generated quite a few comments, so I thought I'd direct some of these visitors to a few forums they might want to check out.
First, I'll shamelessly recommend my own forum. Sure it's empty, but hey you have to start somewhere! ;)
Probably the best source for tarantula info on the net is the Arachnopets Forum, Arachnoboards. It's very active with novices and experts alike. People are always posting pictures of their T's so you get to see a good variety of the latest and greatest from this amazing hobby.
Another great forum is Spidertalk.net. It's much smaller than Arachnoboards with less traffic, but it's still worth checking out. If you register, they have a mySpiders utility for keeping track of your tarantulas. Here's mine.
There is also the Petbugs forum. The layout isn't as nice as the first two, but it's ok.