audio trigger pads

hi,

i'm not even sure what exactly it is i'm looking for, but my friend is a magician and i do music for his stage show. at one point in the show he pretends to throw coins, and he wants it to sound like the coin is clinking. we have a very good recorded sample of coins clinking that we recorded and edited. what he needs is some small device that he can have on him that he can hit to trigger the sound. any ideas on what might work for him? obviously gotta be small... preferablly have a few pads for a few different soudns for during the act, but for now we're just trying to get this one sound for a short show he's got coming up next month. worse comes to worse we'll just have someone off stage with a keyboard hit it, but it would be cool if the magician could have the trigger on him so he could do it himself.

thanks!

Dave