The above is a QR, quick response, code. Originally they were designed as a 2 dimensional easy to scan bar code. This technology started life supporting components and assemblies moving down production lines. Nowadays you are just as likely to see them on press adverts or posters. Your mobile device will pick up the code by use of a camera and an app to take you straight to a place on the web. The one above leads you to a page on Wikipedia that explains all about QR codes.
A real innovative use is on product packaging. I was in a food shop and saw a code on a bag of potatoes. The code got scanned on my iPhone and then I was looking at a mobile friendly webpage that told me all about the variety and provided cooking tips. The potatoes were now 100% sold to me.
On the other side of this are the uses that have not had much thought. A general full screen website is not a good idea for a link on a QR code. You don’t carry laptops around with scanners on them, this is likely to be a hand held device only.
The one application that really holds the lesson for lack of thought is a poster campaign for road safety in the UK. All this sounds very admirable until you consider location. Each poster is an individual advert above … gent’s urinals in a busy service station. Call me old fashioned but a very unlikely place to pull out a camera phone?