I am surprised nobody has posted this. It seems that the motion sensor has been cracked and freelance developers are coming up w/ some pretty cool ways to use it:
http://hardware.slashdot.org/article.pl?sid=05/03/21/1243229&tid=180&tid=3
http://hardware.slashdot.org/article.pl?sid=05/03/21/1243229&tid=180&tid=3