Your Gmail address also becomes OpenID
After the recent announcement from Microsoft about their Hotmail/Live accounts becoming OpenID logins, Google also announced today that they are enabling OpenID support for their Gmail accounts. Participating websites can now accept millions of existing Gmail account holders.
OpenID gaining popularity : Windows Live ID becomes OpenID compatible
OpenID is a free and simple way of using a single online identity across several other participating websites. Though the idea of single online identity has been around for a long time (Microsoft’s Passport logins anyone?), but only recently the idea of OpenID started gaining momentum.