I got chatting to two gentlemen from auqaMobile who had come by the Symbian stand to watch our demos. They have a clever product called Clic2c which can embed URLs into images by adding a bit of noise. Then there is an app which runs on your phone (they demo'd this on a Nokia N73 so they obviously have an S60 app) which uses the phone's camera to snap these images, extract the URL and open it in the browser. I was impressed how quickly this worked on their N73.
This is similar to 2D barcodes and their numerous variations but seems to be more elegant since the data can be directly embedded into photos and other images.