Incredible Machines
Those Rube Goldberg machines as implemented by a Japanese company.
http://www.youtube.com/watch?v=JD8P4fE8Yn0
Cross Your Eyes!
3D images when you cross your eyes. Make sure to check out the rotating ones in the middle.
Fluid Effect
portfolio -> agree -> before/after
Craziness. This shows how much Photoshop can change the way celebrities look.