I'm using 2.6.2 and i don't see it in there, what am i missing? just combed the settings pane too and did not see anything. :-)
that yubikey thing seemed appealing, and had looked at it before, but i dont use things that need 2fa enough to justify the 60 or 120 or whatever it cost... :) although it's a cool thing, regardless.
it reminded me of a place i worked at, that had those old RSA password cards, you'd need to type in whatever it was showing to boot the work laptop, for instance.