On Fri, May 18, 2012 at 1:23 AM, gregrwm <tclug1 at whitleymott.net> wrote:
> i've seen mention of a pam approach, but no detail yet..

There are instructions on the site I linked to:

http://code.google.com/p/google-authenticator/wiki/PamModuleInstructions

After cloning out the hg repository, you build the PAM, add a line to
your PAM config to pull in the new authentication module, and then go
through a quick bootstrap/initialization process to set up your token.