Many.It's bad. Right now this is the only one I really frequent though. I am a mod at a mommy board , it's slooow there lately... and a member of a good dozen or so parenting boards that I once posted at then forgot about. LOADS of other boards that I joined , looked around, posted a little then lost interest. Does plurk/twitter count?
i am a member,,well we are members of several other forums. we only post on a regular basis on two others though.. neither are in any way anything like these forums..
i've randomly signed up at a few over the past few years, but like others have only made a few posts then didnt really return. this one just seemed to suck me in.