Cardboard is a simple experimental project by Google that transforms an Android smartphone into a basic virtual reality headset using what amounts to a little cardboard, a couple lenses, and some magnets. The project has uploaded design files for the physical headset and some documentation to help developers code software to use with the device.
The project first started as a prototype by David Coz and Damien Henry at the Google Cultural Institute in Paris before expanding out from there. A demo app is available on Android.
photos via Cardboard