SixthSense relies on a larger display by projecting visual information onto surfaces, walls, or other physical objects. The camera requires visual-tracking fi ducials placed at the tip of the user’s fi ngers to decode gestures. Applications are plentiful. For example, SixthSense can project live video news onto a newspaper, and users can employ gestures to manipulate a virtual page. As in all gesture systems, defining a broad, yet simpleto-learn gesture vocabulary is a challenge.