I have been an advocate of QR Codes for the past year, having discovered their use by the techno-savvy and techno-barmy Japanese. It now appears that Facebook is set to implement them, according to a number of Tweets and an article just now over on TechCrunch.
You will find one on my contact page which is actually just a link to my website (which will automatically format for mobile phones so that a QR code makes sense), but I use this to demonstrate what a QR Code can do for businesses. I also use them on my business card to link to my website, and with the addition of a URL-shortening service such as Bit.ly you can track the links. Then you can also change the destination as required, by using redirects on your server or any number of other tricks. The QR Code destination itself can be modified at source – I use BeeTagg‘s code generator where you can monitor clicks and change the destination.
I also created a tee-shirt with one of my QR codes on it. It’s not the sort of thing I would necessarily wear out in public, but it proves a point at least!