Today in New York City, HP revealed "for the first time outside of the lab" a concept handheld for the company's Mediascape (or "Mscape") gaming software. The handheld has been sighted before, though - specifically in an HP commercial shown earlier this year at a technology summit.
As seen in the video, the concept with Mscape is that the handheld's screen acts kind of like a lens through which the real world is rendered just like a video game. For example, holding it up to a part of the street may reveal a virtual crater where the ground should be. It's not actually rendering the environment in real time; Mscape cues up the proper graphics when prompted by sensors on the device, including GPS.