Imagine directions to a new location not stopping at the street address, or never getting lost in a new building again. Or, how about playing hide-and-seek in your house with your favorite game character or competing against a friend "for control over physical space with your own miniature army"?

That's the promise behind Project Tango, a new Google initiative which seeks to give mobile devices "a human-scale understanding of space and motion".

The brainchild of Google's Advanced Technology and Projects group, Project Tango is, on the surface, an unimpressive Android phone with a five-inch display and a four-megapixel camera.

But scratch deeper and you'll find custom hardware like two Computer Vision Processors, sensors for measuring geometry and seeing in three dimensions, a camera which tracks motion and other goodies that basically turn this handset into a device that can map your environments, track its motion in full 3D space and much more...