I just returned to the US after two years away. I find the QR codes for restaurant menus to be one of the worst applications. I'm at a restaurant to get offline, enjoy my dinner and socialize. The last thing I want is to start the experience using a smart phone.

I do like QR codes on WiFi routers for connecting to the WiFi quickly, and in apps to easily share credentials and links with other devices. QR codes that share contact cards would be a great addition to a business card.