This is one of the geekiest things I have seen for a while. Barry Jones, one half of the Scottish comedy magicians ‘Barry and Stuart‘ has made a deck of marked cards with QR Codes. They could have been geekier if Barry had left the card faces blank! (Thanks to Michael for the heads-up)

Images from Barry and Stuarts blog.
Hello, can you distinguish the card number from the qr code?
Are the qr codes recognizable for humans?
greets
Kees
Well, I guess yes because each card has a different QR Code. I wouldn’t want the job of learning them though 🙂