I just had an awesome idea, sparked by a post on
renegadekitsune's LJ: Cosplayer Bingo. Cards with short text descriptions of things to look for, both characters and general descriptions. You sit at your artist alley table or wherever with your friends, each one gets a card, and you mark them as you see them. The first player to complete a five-marker line wins. Or, if you're hardcore, the person who fills in the entire card first wins.
So: give me ideas!
Examples:
--Sesshoumaru
--Sanzo
--Male crossplaying as a female
--Female crossplaying as a male
--Cosplayer of ambiguous gender
--Female version of male character
--Prop over six feet in length
--Cosplayer unable to see out of costume
--Costume wider than the cosplayer's height
--A group of three or more cosplaying the same character
--Wings on a character that does not wear them in canon
--A non-cosplayer carrying a keyblade
--A witty twist on a common character (i.e. Sephiroth wandering around with a tiny Aeris doll stuck on his sword.)
Etc.
ETA: -- A Star Trek character at an anime convention.