Once all of our roads and rivers, buildings and parks, shops and monuments are mapped, there will remain one territory largely beyond the reach of GPS: the great indoors.
Right now, Google Maps can take you to the entrance of the Mall of America. But it can't narrate your route to the Aldo. It can drop you on the nonsensical campus of MIT, but it can't help you find the door to suite 9-209. Cutting-edge maps of all kinds can show you the location but not the interior of convention centers, airports, offices or apartment buildings.
As for exactly how this will be possible, Google's Advanced Technology and Projects group unveiled a prototype Android smartphone this week that does a lot more than track your global position as you move through the world. The phone also includes a motion-tracking camera and depth-sensing technology capable of constructing a 3D model of the environment around it. (And it looks more ambitious than a couple of other fledgling efforts at indoor mapping.)
In short, it could help you (and Google?) map your living room, your office complex, or the back booth at your neighborhood diner.
In the below video introducing the project, Googler Johnny Chung Lee explains the impetus for the idea this way: "We are physical beings that live in a 3D world, yet mobile devices today assume that the physical world ends at the boundaries of the screen. Our goal is to give mobile devices a human-scale understanding of space and motion."