The Electronic Bubble Wrap Keychain from ThinkGeek ($10) is exactly what it sounds like. It's a little keychain with 8 buttons, and every time you push one it makes a popping noise like bubble wrap. For every 100 pops it rewards you with a round of applause or some other noise. You know, this thing reminds me of the Snap Your Fingers keychain I tried to market a few years back.
Video after the jump.
Electronic bubble wrap keychain [core77]