...musical greeting card? I came up with this idea for a locker prank but I'm not sure how to design what I need. I want to be able to have something recorded on a small device and then put it in someones locker and when they open their locker door, it plays back, just like a greeting card would. I dont know what parts I need though and it has to be small, portible, and moveable. Anybody have any ideas?