Google is making 200 development kits of the 3D-sensing Tango phone available in order to push the technology further. 

Google’s Advanced Technology and Projects group (ATAP), formerly a division of Motorola, has announced Project Tango, in which it has been working with academic and industrial partners from nine countries, and utilized research from the last decade in the areas of robotics and computer vision. According to Google the goal of the project is "to give mobile devices a human scale understanding of space and motion". 

In practice, this means that future mobile devices could have the ability to sense 3D-motion and geometry, allowing them to capture 3D-scans of their environment and use the data to create 3D-maps or game environments, among other things. Google's Project Tango page puts it this way:

"What if you could capture the dimensions of your home simply by walking around with your phone before you went furniture shopping? What if directions to a new location didn't stop at the street address? What if you never again found yourself lost in a new building? What if the visually-impaired could navigate unassisted in unfamiliar indoor places? What if you could search for a product and see where the exact shelf is located in a super-store?"

An early prototype device has a 5-inch screen and is running Android. It is capable of tracking its full 3D motion and simultaneously creating a map of the environment. The sensors in the phone capture over a quarter million 3D measurements per second. The device's position and orientation is updated in real-time and the data combined into a single 3D-model of the space around it.

"Imagine playing hide-and-seek in your house with your favorite game character, or transforming the hallways into a tree-lined path. Imagine competing against a friend for control over territories in your home with your own miniature army, or hiding secret virtual treasures in physical places around the world?"

We can even imagine being able to see how a virtual piece of furniture would look and fit into a given location in a room before buying it.

The Tango phone includes development APIs to provide position, orientation and depth data to standard Android applications written in Java, C/C++, as well as the Unity Game Engine. The hardware includes a 4MP camera, two computer vision processors, an integrated depth sensor and a motion tracker. 

To push the technology forward Google is making 200 development kits available to be used in for projects in the areas of indoor navigation/mapping, single/multiplayer games that use physical space, and new algorithms for processing sensor data. They have also reserved some units for other applications, that haven't been though of yet. You can apply for a development kit and find out more about the project on Google's Project Tango website. TechCrunch has also found an actual 3D indoor map that has been created with the Tango phone.