Most major Web companies – Google, Yahoo, Microsoft, etc. – have announced support for OpenID, meaning that you can use your credentials from any one of those services to register and login to third-party websites that support OpenID. But Facebook is taking a big leap beyond all of these companies today by enabling you to login to its own site using either Gmail or OpenID.

That means that if you’re not one of the 200 million people on Facebook yet (ok, you probably are, but for everyone else …), you can now signup using the same username and password you use to login to Gmail, or, in a bit more cumbersome fashion using an OpenID URL from another identity provider. A bit more on how it works, from Facebook:

“Existing and new users can now link their Facebook accounts with their Gmail accounts or with accounts from those OpenID providers that support automatic login. Once a user links his or her account with a Gmail address or an OpenID URL, logs in to that account, then goes to Facebook, that user will already be logged in to Facebook.”

The implementation doesn’t seem to be live yet for everyone, but the focus on Gmail is especially interesting, given Google, through Friend Connect, is a bit of a competitor to Facebook, and Facebook, MySpace, and Google are all offering identity platforms of their own that would seemingly compete with OpenID.







But, the integration seems to serve Facebook’s goal of establishing your social graph on the site, by helping you friend your existing Gmail contacts that use the social network. Facebook adds that Gmail users “get up and running after registering even faster than before, find their friends easily, and quickly engage on the site.”

This is big news in the world of OpenID, and it will be interesting to see if it paves the way for other major Web companies that have become identity providers to also do what Facebook is doing – becoming what’s known as a “relying party" and, for example, letting you login to Gmail with your Yahoo credentials.

See Also: 40+ Eye-Opening OpenID Sites and Services