Deskrama is a low-cost interactive space browser for three dimensional architectural designs. You move the screen on top of a drawing and it shows the 3D rendered picture of the building.

No point in trying to explain this here. Just click play and the video will show you how it works. Credits to Mr. Takehiko Nagakura.

http://flash.revver.com/player/1.0/player.swf

Link to video on Revver.