Demon Monkey Shooter by Zi Ye and Chris Perez
Demon Monkey shooter is an FPS that uses a squash racket as its main input device, no strings attached (pun intended). The racket's movements are tracked using a Vicon motion capture system. This is quite a step up from the Wiimote. And yes, we can probably do tennis too.
Demon Monkey Shooter from Zi Ye on Vimeo.