Tom Kraeutler from The Money Pit demos Lutron Maestro Occupancy Sensing Switch, which can be used in virtually any room of the home, and installed in 15 minutes or less. Lutron Sensors feature reliable ALD (auto light detect) sensing technology that detects fine motion and only turns lights on when needed.
Links:
[1] http://www.youtube.com/watch?v=nBJRYwx_8ZA