I've been using 2-factor auth for more than a year, and it's easier than I originally thought. Safer than otherwise, very reliable, relatively painless... What is great is that there's a PAM module of Google Authenticator as well, so you can add another layer to your own Linux servers. Very useful. Here's a good tutorial: http://www.kgarner.com/blog/archives/2011/02/22/google-authenticator-and-implementing-it-on-linux/