- Download the free Snappr application for the iPhone and iPod touch (iTunes).
- Scan the 2D Codes and (the first of it's kind) 1D Barcodes found on books and movies and stuff and get all kinds of price and shopping information.
1D Barcodes work best with a macro lens like the one in the Clarifi-Case by Griffin Technology. Or you can hack together your own iPhone macro lens or make one with the lens from a disposable camera (Instructables.com post coming soon).
2D Codes are the funky square codes (pictured) that can be used to virtually identify anything. You can make them yourself for free on the Web.
If you don't want to install the Snappr.net iPhone application, you can still browse and search product information at http://snappr.mobi.
(Tip: David Comeau)