"Cardboard is a simple DIY enclosure that transforms a phone into a basic virtual reality headset and the accompanying open software toolkit. Cardboard makes it easy for both users and developers to experiment with VR"
Cardboard - Android Apps on Google Play
Google Cardboard VR toolkit | DODOcase
$19.95 - $24.95
Google Cardboard Was the Ultimate WTF Moment of Google I/O
Cardboard @ appspot
'Cardboard' is Google's attempt at an inexpensive VR headset @ engadget