It’s one of these things you should ignore, but size can make a difference, as this initiative demonstrates. GoDaddy.com placed a gigantic billboard on NYC’s Times Square, and it at least got my attention.
I personally was always the opinion QR codes are not a great driver for marketing, since it doesn’t work without the proper application on your smartphone, and it’s often easier just to remember an URL. But this definitely seems to work, it at least got reposted to my social networks. The final URL is less rewarding, but it’s the journey, not the destination.
If you are looking to implement your own QR code functionality, Adobe AIR works with existing AS3 QR code libraries, meaning you can easily integrate the functionality in your mobile application. Brian Rinaldi has a great example with source code.