The above image is a QR Code. These two d codes are remarkably versatile. You can store just about any text in them. Things typically encoded this way include contact information, addresses, and web urls. Most smart phone manufacturers support at least scanning the contact information (e.g VCARD), but Google supports a whole range of other uses.
One of the more interesting uses Google supports is encoding a text string representing an application in the Google Market. When the example above is scanned into a Android based phone, it will launch an app I’ve been working on called RecallCheck (see below for more details).
This week the Google announced it was implementing QR Code stickers for businesses to put in their window. When scanned into an Google Android phone, they will bring up information about the business from Google. Expect to see a lot more about QR codes in the coming years as they work to connect the physical world with the Internet via phones.