Facebook has taken steps in the past to promote sharing identities across different social networks, with its own Facebook Connect and its membership on the OpenID board, and it just took one more big leap by allowing Facebook logins via OpenID. If you have an OpenID from a provider like Google, you can now login automatically to Facebook. You can also register for Facebook using a Gmail account, which Facebook is hoping will boost its membership numbers.

According to the Developer Blog, users who register with OpenID are more likely to become active Facebook users. That means Facebook has every reason to support OpenID, even though it competes in some ways with Facebook Connect. The reason Facebook initially limited registration to workplaces and Universities was that those emails could fairly reliably verify a user's identity. It's nice to see that OpenID has achieved the same level of legitimacy.