Patrick Donnelly has had an interesting idea and is looking for help to make it a reality (email is on his website) - QR Codes on the sole of your shoes (image below). I am not sure how they could be kept readable given the contrast requirements between the dark and light squares, any ideas?

I would love it when I’m walking with my dog, and it’s snowing, and the person before me would make such marks in the snow
winkelwagen,
I think it would be a good promotional tool if the company did it right and put the code in a mirror image that way the foot print could be used for scanning. Silly company. Good idea, but needs refined….
Just my 2 cents….
He keeps them coming, doesn’t he?
Here’s the answer to the two colour issue: http://www.vibram.com/
They would probably be interested in doing this.
Haha. Cannot believe I have just stumbled across this - especially after only predicting this would happen in my QR Blog article
http://www.designinc.co.uk/design-blog/creating-qr-codes