3D environment navigation with the WiiMote
The University of Western Australia has created a cheap way to navigate immersive 3D environments. To accomplish this task, they modify DarwiinRemote for OS X. The WiiRemote provided a low cost alternative to other controllers used for immersive environemnts.
If you're looking for a .Net approach of interfacing with the Wii, check out Brian Peek's implementation for the WiiMote.