The problem at the moment is that I don't tend to see any magazines, etc., which have these 2D barcodes on them. It would be cool, but only once the barcodes are being used.

Not so sure about the 1D barcodes on items in shops, is there a large database in the sky listing what is what?

For books it would work well as it encodes the ISBN (I wrote some MATLAB code to scan in 1D barcodes and was going to port it to Python so I could take my Nxxx out with me and know whether I already had a given book, but the N810 only has the one camera, facing the wrong way, so I've lost interest for the time being).