RigReference.com places QR-Codes on many pages. But what are they?
QR-Codes are two-dimensional bar codes readable by mobile phone cameras. A QR-Code can contain up to 4kB of data, really useful for storing web site urls. See an interesting page but don't have time to jot down the url? Simply take a picture of the QR-Code with your mobile and you have all the data you need.
An in-depth description can be found on WikiPedia.
Which phones can scan QR-Codes?
A variety of cell phones are compatible with QR software. HP, HTC, LG Electronics, Motorola, Nokia, Palm, Pantech, RIM Blackberry, Samsung and Sony Ericsson are among QR-ready phones. If you're phone maker isn't listed here, don't worry. QR readers are also programmed for Java-enabled and Windows mobile devices. Just make sure your gadget has a camera phone!
Download a QR-Code reader
For iPhone users: search for either NeoRader or i-nigma in the Apple App Store.
Other mobile users can download the Kaywa Reader. This reader runs on many mobile devices and gives quite good results.