Have you seen these wierd little things showing up in unexpected places? They are called QR codes and they seem to be poised to become the next big thing. The link below is to Wikipedia and the article explains them well.
The idea is that you can take a photo of the QR code with your phone and then an application in the phone will interpret the code. Kind of like a bar code for business cards or…whatever.
QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards, or on just about any object about which users might need information. Users with a camera phone equipped with the correct reader application can scan the image of the QR Code to display text, contact information, connect to a wireless network, or open a web page in the phone’s browser. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks.