Here are some links if you want to play around with QR Code. There are several programs for cellphones and the like that will read QR Code.
http://zxing.appspot.com/generator/
http://zxing.org/w/decode.jspx
You encode plain text. But the cool thing is that there are plain text formats for contacts, calendar events, etc. So if the reader software is smart, it could automatically act on the information contained in the QR Code (Like open a URL).