The Disney codes are cool - they are creative in a way that doesn't compromise the readability of the code. The others just seem like gigantically bad ideas.
It's hard enough convincing people to use QR codes - the more you violate the spec the more devices will stop reading it.
The "Barcode Scanner" app in the Android market had trouble with the first one, and the one with the panda in it. Google Goggles had no trouble with any of them.
QR codes use Reed-Solomon error correction which means between 7% and 30% of the image data can be lost but the encoded text will still be readable. Digital TV / radio broadcasts use a similar system.
These examples are taking a slice of that redundancy and replacing it with a design. This is a bit like using typography to make a URL look nicer but harder for a human to read.
All the paperlinks ones scanned almost immediately (redlaser here, could use a better one if anyone knows any). The rest usually took some jiggling and trying for a minute or so. And the Disney ones were just too small.
The Disney codes are cool - they are creative in a way that doesn't compromise the readability of the code. The others just seem like gigantically bad ideas.
It's hard enough convincing people to use QR codes - the more you violate the spec the more devices will stop reading it.