I LOVE the weekender threads. There's always such excitement on them. Or is it "in" them? I never know whether to say "on" or "in" when I'm hanging out in the forum...or is it "on" the forum.... LOL
LOL I think it depends on context - if you're discussing a thread or a forum as distinct software entities in themselves you'd probably say 'on'...
if you look at them as groups of people, it's probably more grammatically correct to say 'in'.
mebbe?
D