This site is pretty old, but I just Stumbled on it tonight. With it, you can see a number of ways to use the iSight with Motion Sensing on the MacBooks and MacBook Pros.
As you know, the last Powerbooks and the MacBooks have motion sensor to protect the hard drive in case of a drop of the book.
One of the applications mentioned here is Light Saber. (I think the iPhone version makes better sense.)
Another one is Dash Level, a dashboard widget that turns your mac into a level.
For the camera, Evocam is the first listed.
Miracle sight uses motion triggers to turn your mac into a magic mirror.
To get the complete article, go here: http://www.mexicanpictures.com/headingeast/2006/06/motion-sensing-and-isight-hacks-on-mac.html
