A few games that are actually fun using augmented reality with your android device and its camera.
A graphic and interesting sniper game for your android phone.
PhotoShoot – The Duel
2 android phones needed but a cool app that lets you duel with friends.
Sky Siege Arcade
Takes the world around you and adds planes that you have to shoot down.
Parallel Kingdom MMO
An RPG that takes the virtual world and overlays it on your world. Lots of RPG elements in the game.