Http://www.gadgetx.com/blog/2010/4/16/brainstorming-the-future-1-qr-codes.html

New concept in QR-Codes, using Infrared light to embed or overlay codes on objects. These codes are detectable by image sensors in mobile phones yet invisible to the human eye. The video covers sign-age applications of Infrared QR, what else can we with these invisible codes?

Anthony