QR stands for "Quick Response" and they look like this:
You have to first download a QR code reader app for your iPod (the kind with a camera) or smartphone, but there are plenty available.
Then just point your camera phone at the code (e.g., on your email screen) and it will read the URL and take you to: http://hol.wirenode.mobi
-- which is a mobile website for a teacher conference here in Singapore.
Text, SMS messages, URLs, and phone numbers can be encoded in a QR code.
Have a go!
Then start thinking about how these could be used..... We have some ideas to share with you.