I don't begrudge people using QR codes but to me, they seem like a poor solution for a real problem. We need a way for a computer to interpret analog information from the real world. QR codes just make the problem worse for me. I see them on bus stops and billboards all the time. I used to see URL’s instead. At least a URL is legible (most of the time). QR Codes are completely obscured from human interpretation. Should I point my browser at any QR code? I would not visit a completely obscured URL without knowing for sure where it would take me. A better solution would be to expand the capabilities of OCR and force our computers to interpret the information that humans are already using: written language.
I now have a number of apps on my iPhone that can effectively interpret written language, like OCRKit and Abbyy TextGrabber. In fact, the free Abbyy LinkGrabber app does a pretty good job reading links from a photo. Why not use that ability? Skip the QR codes, they're an inferior crutch. Just demand better OCR apps (and support the ones that exist).