By now everybody knows that it is possible to slap a logo in the middle of a QR code and — provided enough redundant data remains — the result will still be readable.
It seems it is also possible to engineer the encoded values to create a picture across the entire QR code. This technique not only produces a highly distinctive code image, it also produces completely legitimate codes.
Russ Cox calls these QArt codes, and has developed a web tool for producing them: QArt Coder. All the source code is hosted at code.google.com/p/rsc/source/browse/qr.
QR Codes are a great idea but they are big and ugly. You can customise them to a degree, but they still lack personality. For example, here are some I made to print as Moo stickers:
There is also the Microsoft tag, but that looks even worse.
I wonder if it would be possible to create another type of code that works in the same way, but instead of generating a random checkerboard pattern, it created some kind of face. I’ve quickly drawn up two examples of what these could look like (at the top), but I imagine a much more detailed/abstract look would be required to accommodate the amount of information they would need to contain.