QR codes might work better for low-res cellphone cameras. I have a QR reader (http://reader.kaywa.com/ http://reader.kaywa.com/) on my phone and it works pretty

QR codes might work better for low-res cellphone cameras. I have a QR reader (http://reader.kaywa.com/ http://reader.kaywa.com/) on my phone and it works pretty well, even with only .3 megapixels. I never use it though, since QR codes don't seem to have much uptake (yet?) in the US.