I note this just because Chet has had interchanges with him in the past...
Steve Gibson, of SpinRite fame has come up with sort of a super-simple variation on the little RSA keyfobs where you instead carry around a little business card that you can print up yourself that has a bunch of possible second-factor entries you can use for auth.
The part that makes me laugh a bit is that it is--as you might expect if you remember the ads for SpinRite back in the day--a Windows .DLL coded in assembly.
John Graham-Cumming has a C implementation of the scheme. He also has a three-letter domain name. Coincidence?