What's This? Cardboard from the Cardboard project given to Google I/O attendees. Image: Mashable Pete Pachal By Christina Warren2014-06-25 20:52:34 UTC After a marathon two-and-a-half hour Google I/O keynote, the tech giant had one final surprise for attendees: a piece of cardboard. Developers at I/O walked away with a strange construction kit for a project named, imaginatively, Cardboard. See also: Google I/O 2014: Everything You Need to Know Cardboard is a way to create an Oculus Rift-like virtual reality viewer with your Android smartphone. Users can put together their Cardboard kits which contains corrugated cardboard, some lenses, magnets, two strips of velcro and a rubber band. Put it together along with your Android smartphone and this is what you get. Image: Google If you didn't get one of these kits in person, you can build your own using these design files. VR on the cheap Google wants developers to combine Cardboard with its experimental VR Toolkit to bu...