Now this is very cool
Funai Electric Co Ltd and Nippon Signal Co Ltd developed an ultra-small color laser projector that can not only project an image but also recognize finger movements on the image.
Users can rotate, enlarge and replace a projected image by moving a finger on it. Therefore, the new projector can add a function of touch sensitive display to the front surface of a refrigerator, a whiteboard and a wall in a room at low cost.
More
http://techon.nikkeibp.co.jp/english/NEWS_EN/20091005/176036/