I don't think I've ever wanted to do a DIY project more than this one. It's a real life coin block lifted straight from Super Mario. So when you punch the bottom of the box, like Mario so often did, coins shoot out of the top (it even makes that classic sound!).
The project is a little more complicated for my skills can typically handle, involving heavy use of springs, levers, timers, servos, soldering and an MP3 player, but can you imagine having this instead of a jar of change? So much more fun. Oh you need change? Punch. Punch. There you go. [Instructables]