That looks just like what we should have

The library they're using is zxing, which does 2D & 1D barcodes (good), but is written in Java (not so good).

Thanks , the image processing bit is what will make it fun, but against that (as it will take a while to write my own) is the fact that I should get something working asap to keep up momentum (i.e. use existing libs).

Looks like it uses a backend server to avoid lots of bandwidth-expensive looking at the different websites. Sounds good