How to Use QR Codes

What is a QR Code?
QR or Quick Response Codes are a type of two-dimensional barcode that can be read using smartphones and dedicated QR reading devices, that link directly to text, emails, websites, phone numbers and more. Ordinarily we think of a barcode as a collection of vertical lines; 2D Barcodes or QR Codes are different in that the data is stored in both directions and can be scanned vertically or horizontally.
How do I scan a QR Code?
If you have a smartphone like an iPhone, Android or Blackberry then there a number of different barcode scanner applications such as Red Laser, Barcode Scanner and QR Scanner that can read and decode data from a QR code. The majority of these are completely free, and all you have to do once you install one is to use your phone's camera to scan the barcode, which will then automatically load the encoded data for you.