https://sites.google.com/site/mechatron ightscythe
This is a pretty cool project. The idea is that you have an individually programmable RGB LED strip that you modulate over time, while walking in front of a camera. With a long enough exposure, you get a 2D image. But the really cool aspect is that the camera will also capture the shadow of the thing, giving the impression that you actually have a plane of light floating mid-air.