Makey Makey Standard Kit, $49.99
The Makey Makey can turn nearly anything into a computer input. All you have to do it take it out of the box, plug it into your computer, and attach a wire onto something somewhat conductive and it becomes a computer key. You can play the national anthem by eating your lunch or Pac-Man with Play-Dough. It can be used by just about anyone with a little imagination and since it’s Arduino based, you can hack it if you ever feel like it. It’s a great way to explore interactivity in a completely new way.