Duo offers a number of features above and beyond Google Authenticator: - more flexibility in choice of authentication method (voice, SMS, soft token, hard toke

Duo offers a number of features above and beyond Google Authenticator: - more flexibility in choice of authentication method (voice, SMS, soft token, hard token, Duo Push) - more supported mobile platforms (Android, iPhone, Blackberry, WinMo, Palm WebOS, Symbian, J2ME) - more integrations (VPNs, UNIX logins, web apps, etc) Not to mention all the features that come along with being a fully-fledged authentication service such as account management, fraud alerting, logging, etc. Feel free to give it a shot and decide for yourself. :-) Disclaimer: if it's not obvious from my gushing, I'm affiliated with Duo. ;-)