Simpler trick that's easier to set up anywhere. (I used to do this at the pizza shop all the time when I was bored.)
Glass of water & a coin. Bet someone you can get the coin out from under the glass and into your pocket & they won't see you touch the coin. Start tapping the table on both sides of the glass, slowly, then start building up, start saying some chants or something - anything to get your victim to lean closer. Grab the glass, throw the water in their face, and casually put the coin into your pocket. Works best with witnesses - preferably the victims friends, who get to share in the laughter. I've *never* seen someone not fall for this, of course, that was with drink cups that weren't see-through; that might have aided the "magical-factor" of the trick.