Common in Japan, where it was created by Toyota subsidiary Denso-Wave in 1994, the QR code is one of the most popular types of two-dimensional barcodes. QR is the abbreviation for Quick Response, as the creator intended the code to allow its contents to be decoded at high speed.

A QR Code (it stands for "Quick Response") is a mobile phone readable barcode that's been big in Japan forever, broke into Eurpoe a while back, and is now getting traction in USA and Canada.

Download Free QR Scanners

1. For the iPhone: http://itunes.apple.com/app/id368494609?mt=8
   
2. For the Blackberry: http://appworld.blackberry.com/webstore/content/13962
3. For the Androids: http://www.appbrain.com/app/quickmark-qr-code-reader/tw.com.quickmark

In it's simplest sense think "print based hypertext link" - simply encode a URL into the QR Code and then point a mobile phone (or other camera-enabled mobile) at it. If the device has had QR Code decoding software installed on it, it will fire up its browser and go straight to that URL.

Although initially used for tracking parts in vehicle manufacturing, QR codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (termed mobile tagging). QR codes can be used to display text to the user, to add a vCard contact to the user's device, to open a Uniform Resource Identifier (URI) or to compose an email or text message. Users can also generate and print their own QR codes for others to scan and use by visiting one of several free QR code generating sites.

QR codes storing addresses and Uniform Resource Locators (URLs) may appear in magazines, on signs, buses, business cards, or almost 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 termed hardlinking or object hyperlinking.

Google's mobile Android operating system supports QR codes by natively including the barcode scanner (ZXing) on some models, and the browser supports URI redirection, which allows QR codes to send metadata to existing applications on the device.

 But it doesn't stop there - a QR Code can also contain a phone number, an SMS message, V-Card data or just plain alphanumeric text, and the scanning device will respond by opening up the correct application to handle the encoded data appropriately courtesy of the FNC1 Application Identifiers that are embedded in the encoded data.