We are at the WorldCon in Toronto. Within half an hour of me putting on my badge, Elizabeth invented a trick to play on people wearing Torcon badges: the string on the badge holder is elastic. If grabbed and released, it snaps very nicely. On bare skin, that hurts. Try it on your friends! Try it on people in skimpy costumes! Or better yet, replace your elastic string with one that doesn't stretch. That's certainly on my todo list.