Depends on the venue. Sometimes it's at a fish store, sometimes there's a speakers, other times it's an informal session with hands-on demos. At all of them, everybody mingles for a while, chats, trade frags, etc - nobody's forced to do anything (except respect the speaker when they're in their talk). It's really what you want to make of it.
FutureInterest- great reference- Fight Club is one of my favorite movies...
TriGa22- cool to see that you're into RC Planes- I did that for a while, until I got caught up into aquariums...