Jo,
Good question!
Yes, I do use other travel forums, some more than others. At the moment my time is somewhat limited by "work" so I only have time for this site and one other message board on a regular basis. My situation will be changing next Monday morning, so I'll likely be here more often!
Here are the sites I use most frequently:
RS HelpLine
Guide For Europe (often not as "busy" as the HelpLine but it's a nice, friendly smaller message board; it's usually a bit quiet in the winter and picks up again in the spring, which has been the case this year as well)
Lonely Planet Thorn Tree. (I used to be quite active there, and I'm going to try and check it more often; there used to be more "trolling" and "flaming" there, but not sure if this is still the case?)
Backpack Europe (hopefully I'll soon have time to visit there more often as well)
I've thought about joining Trip Advisor, Fodor's, FlyerTalk or others, but I just don't have the time right now. I'll look at the situation again later in the summer after I return from this year's European adventure.
I'm in the same category as Tim (ND) in that I'm somewhat "older", so in some cases the information from LP isn't quite as relevant for me. My travel style is not "luxury" but it's not "budget" either (although I don't mind staying in Hostels at times, and get along well with the younger crowd). My travels so far (and probably well into the future) are focused solely on Europe, so I have no interest in the other destinations covered there (although their Europe sections are good).
Interesting Thread....