McDonalds have got a pretty cool campaign running in Denmark right now, their Coinoffers app. The idea is to collect virtual 'coins', one million of which have been spread over Denmark in the form of QR codes, and sound clips on the radio and even TV ads. With their Coinoffers app (available in both App Store and Android Market) you can scan the codes, or record the sound clips. Once you have enough 'coins', you can head to McDonands and exchange them for a cheeseburger or carrots or whatever else you want.
I might not be the biggest fan of the fast food chain, but this is a clever idea. Unfortunately the reviews in the Android Market aren't exactly positive (can't open the app in time to record the clip, you have to connect with Facebook etc), but no doubt these points will be addressed. I really like the idea of using an app to collect sound and QR codes, and the fact that it gives the consumer something in return, instead of simply sending them to a website etc. It's a great integration of print, radio, TV and apps, and will be very interesting to see how the campaign does. I can imagine it being very successful in the US or UK, but I'm not convinced that little old Denmark is quite ready for it, mostly because of the QR codes, but I hope I'm wrong.