Google’s new WebGL Bookcase is using QR Codes to enable users to view their selected books mobile pages on books.google.com. This is a Chrome experiment so you will need the Chrome browser and a WebGL enabled graphics card. I was able to read my chosen book (image below) on my smartphone with no problems but WebGL Bookcase itself is resource intensive and you will need a modern PC to get the best results. The video below gives a good idea of how it all looks.

I am seeing more Qr codes being used on desktop sites as a link between the desk and mobile environments. Very exciting, but not alyways useful yet.
-Patrick