Saw the coolest thing the other day at a Lego store: they have a video display with a video camera where you hold up a product box for one of the toy kits they sell, and the camera figures out which kit it is and then displays a 3D, animated sequence that appears on the display to be *on* the box you are holding in your hands.
Lego Store Augmented Reality Display
You can change the position of the box to see the display from various sides and angles, which is very cool.
I was curious to know whether there was some sort of RFID magic going on for the initial image recognition, so I took a picture with my iPhone and then held up the resulting image to the Lego display's video camera to see if the software still would recognize the Lego kit package and run the animation. I was impressed to see that not only did it work, but it was scaled down in size relative to the size of the image on the iPhone's display! The shiny finish of the iPhone display would reflect the bright store lights into the display's camera at certain angles and overpower it, killing the animation, but still, that was pretty cool.
