I wrote a while back that my Yubikey I got from MtGox wasn't reprogrammable, and I thought that was the end of it. It weighs fuck all, and the effort involved in taking it off my keyring wasn't worth the payoff so I kept it on the keys to the Sprinter.
Today I learned that almost a year ago, all the access codes for MtGox Yubikeys were leaked. I downloaded the list and checked for my serial number. Success!
The file is laid out in the following format:
123456A d2868706da69 32e193d3e932 123456B cf0d9f4b8d2b d4deb686e7bc
123456 being the serial number. Open Yubikey Personalization
head to the "Tools" tab, click "Delete configuration". Tick "use access
code" and enter the last column in the box. Line A corresponds to
Configuration Slot 1, Line B corresponds to Slot 2.
Once you've deleted both configurations, you've essentially got a stock Yubikey that you can do whatever you like with it.
Now to try out the PAM module for it.