Needless to say, people gather in large groups for strange reasons. I've seen conventions for armadillo-racing enthusiasts, but I really think this is the best one I've seen in awhile.
Three Days of Dogfighting for the Cure: Probably the most out-there fund raiser... ever. And okay, so they're not actually going to be dogfighting in the skies to bomb the crap out of AIDS, but still. Odd notion.