Google has just unveiled Project Tango, a smartphone with built-in 3D computer vision technology. Think of it as a smartphone with built-in Kinect functionality -- but rather than enable Leap-like gesture control, the computer vision tech is used to create a full 3D map of your current environment. At its most basic, you might use Tango to create a map of your house, or a 3D model of your favorite antique vase or your motorbike. Its advanced uses, though, are what make me truly dizzy with excitement. We are looking at a device that could, in one fell swoop, revolutionize indoor navigation, DIY, shopping, gaming, and more. How? Read on.