Here are two pieces of technology that I think are fancy and magic.
This touch-screen foil product is a transparent foil that you can apply to the back of a window and then plug into a CPU. Put a rear-projection or LCD monitor behind the window and ta-da! Insta-touchscreen!
Heliodisplay is even more magical. It uses compressed air to create a projection surface and infrared to detect if you are touching the display. Check out the free-space interaction video.