I don't mean just SMF boards.
I bet I'm a registered member of at least 30, probably more like 50, but I only post regularly in a half dozen or so.
Some tech forums where you have to register to post, I have registered only to ask a question and never went back, or I only go back once or twice a year.
Do you mod at any forums you don't own?
I'm a global mod at a busy invision board. I was also made a mod at a phpbb that's not very busy and I don't even go there very often.

Hmm, maybe I should check in there sometime this month.