It stands for Quick Response code and is the square, bar-code looking images that are showing up on ads everywhere. A smartphone (or iPad, etc) can scan the code and read the website address that is embedded in the code. It’s faster than typing in long website addresses.
You can create your very own QR code for business cards, Christmas letters, or whatever. After some research, here is the free QR Code generator that I use: http://qrcode.kaywa.com/
There is an article about QR Code generators in the New York Times: ” Q&A: Make a Quick QR Code” http://nyti.ms/OdtmFZ
Happy coding! 🙂