Google/Secure Access

Google Secure Access is a PPTP VPN that lets people bypass the insecure Wi-Fi link in a hotspot by wrapping their traffic in a tunnel.

Since PPTP and CHAP aren't that strong (and have been reported broken in a few occasions), Google has added client software that strengthens the login security by retrieving a one-time password from an SSL server (that seems to be about the only thing it does).