This is a little video of a machine that makes Mario repeatedly punch a block and get a coin. It was made out of LEGO Mindstorm sets and Perler beads. At least I think it was. It could be made out of magic and donkey dicks for all I know.
Hit the jump for the machine in action.
Thanks to Jonathan, who once tried collecting coins out of a brick wall and didn't score anything but a concussion.