Take a look at some of these videos:
PS2 Eyetoy kinetic game
http://www.youtube.com/watch?v=Au4d5anfjnA
PS2 Eye toy waggle thing device
http://www.youtube.com/watch?v=FpNdkm9s8AY
PS3 The Eye tech demo - 2 cups and a water lol
http://www.youtube.com/watch?v=JKkI5QBKFis&feature=related
PS3 The Eye tech demo - draw comes to life
http://www.youtube.com/watch?v=jBA1uWSDYjk&feature=related
PS3 The Eye tech demo - tank battle
http://www.youtube.com/watch?v=hXJPok3NZEk&feature=related
PS3 The Eye tech demo - head tracking
http://www.youtube.com/watch?v=FFN8cW1mSVY
Also PS3 The Eye has a mic embedded so it could possibly take commands and voice recognition as well. Of course it's not as advanced as Natal, but damn it's impressive. Why hasn't Sony developed more stuff for it?
