For an early peek into the future of augmented reality, there's a game due out late this year that uses it.
I've been watching the development of Traveller AR, an iDevice massively multiplayer roleplaying game (MMORPG) based on Marc Miller's classic tabletop RPG Traveller. In addition to the Traveller stuff, the developers (Ingz out of Austin, Texas) are using the iPhone's camera and GPS to overlay gameworld elements onto wherever you happen to be.
I haven't gotten my hands on it yet, so I don't know how well this will work. (Open beta may start sometime in September.) But is anyone surprised that an early application for AR is in computer games?