Nintendo announced their DIY cardboard addon recently, and Dami Lee from the Verge dug into how it all works. The video is a great primer on all the tech involved. Very simply put, it's an IR camera and some stickers for most applications.

Seeing how this works makes me want to buy some, but the responsible adult in me knows I'd barely touch it after I was done, and my plastic Rock Band/Guitar Hero controllers would have some company in the closet. Anyone with curious kids, however, may consider this as a way to kickstart other creative and fun DIY projects.