Rafael Mizrahi sent in a link to his Real Virtual Skater project, a real skateboard turned game controller for use with Tony Hawk Pro Skater.
The deck uses a Wiimote to capture accelerometer data and send it over Bluetooth to software on the PC. This software then sends emulated keystrokes to the game in response to your movement on the deck. It looks like this was presented at GeekCon, and the creators also hacked some of the game skins to put the presenters’ likenesses in the game. Slick.