Any use for now-defunct Mt Gox Yubikey?
The access codes were recently leaked (by whom, I don't know).  My Yubikey is listed and I can confirm that the access codes were necessary and sufficient to reprogram it.  You can change or remove the access code as part of reprogramming too.  The leak doesn't make the Yubikeys useless in the extremely unlikely event of Gox rising from the flames &mdash; no AES keys were leaked, only the reprogramming ("access") codes &mdash; but the AES keys are write-only, so consider whether you care about that unlikely event before doing anything you can't undo.

So go grab the tools, reprogram, and rescue your Yubikey from the TiVo Graveyard.  I think I'll be using mine in static mode only, with one slot unlocking my password manager and the other unlocking an encrypted partition on a headless machine at boot.  If you do something similar, don't forget that (unless similarly headless) you can type a prefix (something-you-know) before hitting the button on the key (something-you-have).