Google unveiled Friend Connect

Now adding a “social component” to your site is as simple as putting a YouTube video or a counter button on it. After the May announcements, Google finally brought Friend
to the public beta stage.

Let me remind you that Friend Connect is a service that allows webmasters to add user authentication modules to the site (now, in addition to Google’s accounts, Yahoo !, AOL and, of course, OpenID are supported), discussions, invitations from friends, etc.
“We know that people in Networks like to make social connections. Friend Connect simplifies authentication on the site, gives you the opportunity to talk about yourself using your personal profile, find new friends with similar interests, or invite old ones to the site. ”
Mussie Shore, Google Product Manager
Original News at Official Google Blog