At the end of Google I/O, Google's annual developers conference on Wednesday, Android boss Sundar Pichai announced that audience members would be getting some swag.

Among the takeaways: A piece of cardboard.

Sure enough, when we left the auditorium, Google employees handed out pieces of cardboard.

At first it looked like nothing much. But after putting it together, we soon learned that with just some cardboard, a magnet, a rubber band, some magnifying glasses, and the Cardboard App, you, too, can fly around a virtual space, just like you can with the Occulus Rift VR glasses.

You can find detailed instructions on how to use it — and even make one for yourself — on Google's site.