GRC's Perfect Paper Passwords works well for me (https://www.grc.com/ppp.htm https://www.grc.com/ppp.htm). It's similar to Last Pass's Grid authentication but l

GRC's Perfect Paper Passwords works well for me (https://www.grc.com/ppp.htm https://www.grc.com/ppp.htm). It's similar to Last Pass's Grid authentication but less obnoxious IMO. One member of the GRC newsgroups has written a PAM which has served all of my 2FA needs (http://code.google.com/p/ppp-pam/ http://code.google.com/p/ppp-pam/).