Sixth Sense Wearable, "Gestural" Interface. Cool.

Check out this TED speech which demos Sixth Sense, a wearable gestural computing interface that augments the physical world with digital information, from Patti Maes at the MIT Media Lab.
The device has both a camera and a projector. It uses the camera to figure out what you are doing (e.g., reading a newspaper, holding a bottle of wine) and then uses the projector to display additional, contextually relevant information (e.g., providing additional real-time updates on a news story, displaying the Parker points for a bottle of wine).
The coolest part is that your hands interact with the projected image to drive the interface.
The funnest example in the demo is the device projecting a tagcloud onto a person (e.g., from his or her blog) after the camera recognizes who it is (at time 6:47).