Yeah, I think this is a great idea, but I am not sure about the comparing part. I like the esthetic value. Can curves be created?
Every shape is possible in theory, however I'm now using a 4x4 image to keep it really small (and fast to generate). Curves means (much) higher resolution.
I see that the same topic came up a few times before (
https://bitcointalk.org/index.php?topic=137406.0 ) but these projects ended and were not executed thoroughly.
I'll try to combine a image with a QRcode today and post it here.
Looking forward to see it.