QR codes (2 dimensional bar codes) have been around for over a decade now.
Whilst useful for inventory control, they have found particular favour in Asia for consumer marketing.
Japanese camera phones enable time pressed salarymen (and women) to snap the QR code of a product or billboard, taking them directly to a mobile advert without the hassle of typing an interminable URL.
According to the Times, Harrods will use the codes in adverts to engage the attention of customers.
The lack of compatible handset software will cause problems, but this is such a useful service I hope it catches on.