To find out what this is about, go and download a QR code reader to your cameraphone. The QR code reader is a piece of software that you open up on your phone and it will use the camera to take a picture of this funny square and then display what information is embedded in the pixels.
I use a reader from i-nigma.com
They have a long list of supported devices, i.e. gadgets you can use to run the QR code reader. I found it better to search for the right software on my laptop and then download it to my phone.
I have found that I tend to stop and scan QR codes now just to see what's there.