No. The only forum I get involved with is the one on HubPages. I use HubPages as my site to go to either in-between offline projects or else when I don't really have much going on "work-schedule-wise". I'm not particularly "an Internet-socializing-type person" (and am pretty much only interested in writing online in my skimmed/spare time (and the usual e.mail, shopping, etc.); so since I'm already familiar with HP and since I write here anyway, it just makes sense to use the forums as my "not-in-the-mood-to-write" activity (but also to sometimes get ideas for writing, either here or elsewhere).
Between writing the occasional Hub, the occasional other thing online, and/or whatever writing I want to do on my own in whatever extra time I have; my extra time is spread pretty thin. Even so, sometimes I'm just too tired to feel like writing (or just not in the mood), which is when "discussing" on the forums or answering some questions on here can come in handy as effortless entertainment. Sometimes (lots of times, in fact) even the otherwise "non-Internet-socializing-type" person needs to just do something for entertainment, rather than for more important purposes.
I'm pretty much a mostly-one-site kind of person when it comes to the casual writing I do. I could switch sites at any time, but I do tend to stick with only one site at a time for the "entertainment/casual writing purposes".