Man I found the neatest thing...
http://fantasticcontraption.com/ It's a Flash-based game where you build a wheeled apparatus to move a red ball into a red square. It gets really hard in the higher levels, check THIS out:
http://FantasticContraption.com/?designId=1195060 That's a saved replay of my game on the highest level I've reached so far. Just hit PLAY then Continue then hit the start button.
The fairly astounding "wonka mobile" I made'll go and fetch a ball, reverse, jump a canyon, climb a ramp and put the ball in the red square! This sounds simple until I mention they only give you spinning tires and frame pieces to build with.
Give that game a shot, it's a hoot. :)