This is still in its experimental stages, but:
The Wiitrack plugin for Compiz, combined with the Wiimote plugin, gives your desktop a truly 3d feel by implementing the same tracking functions used by Johnny Chung Lee, but in Compiz's OpenGL environment.
[youtube]ZYLNprRplmc[/youtube]
Note: The video is old and the person recording it did not spend any time calibrating. Nor did they listen to my suggestions >_>
Rather than bore you with the details, I'll just
link you to the Wiki page.