A QR Code (it stands for "Quick Response") is a mobile phone readable barcode that's been big in Japan forever, broke into Eurpoe & the US a while back. In it's simplest sense think "print based hypertext link" – we can simply encode a URL into the QR Code and then point a mobile phone at it, and the viewer has an abundance of information in their hand! We can set up and register QR Codes for all sorts of things!