Google is releasing a preview version of Friend Connect, a service designed to let Web publishers add social networking features to their sites.

Friend Connect, which is available on the Web, lets publishers add social networking applications by inserting "a snippet of code" in their sites, Google said.

"We're seeing social capabilities get baked into the infrastructure of the Web," said David Glazer, director of engineering at Google, at a press conference to launch the service. "[They're] increasingly not tied to any one site, to any one source of friends, or any one type of application. We see the Web moving towards an end state where people can use any apps on any Web sites with any of their friends."

Thus, sites will be able to add features like user registration, friends invitation and message posting, and allow visitors to interact with their existing friends at social networking sites like Facebook, Google's Orkut, Plaxo and Hi5, according to Google.

"Google Friend Connect is like giving Webmasters a saltshaker full of 'social' that they can sprinkle on their sites to add social capabilities," Glazer said.

Google's move is yet another in a recent string of data-portability efforts aimed at tearing down the walls in social networking sites and letting users export the data and content they have stored in those sites. MySpace and Facebook took steps in that direction with announcements last week.

As the popularity of social networks keeps rising and people set up multiple profiles, they are demanding the ability to carry their data, content and connections from one site to another, so that they don't have to reenter all that information again.

At the same time, Web publishers are eager to latch onto the craze by adding social networking features to their sites, now that a critical mass of Internet users have embraced the interaction and sharing that social applications provide.

Friend Connect uses open standards for authentication and authorization like OpenID and OAuth, and makes any Web site a potential "container" of social applications built with Google's OpenSocial APIs, Glazer said.

"The entire Web has become a container for OpenSocial apps," he said.

Monday night (in the US), Web publishers will be able to sign up to a waiting list to get access to the Friend Connect service, but Google expects to make the service available to anyone within the coming months, officials said.

The back-to-back unveiling of initiatives from Google, MySpace and Facebook, with their differences and limitations, signal both progress and confusion for data portability, Gartner analyst Ray Valdes said.

"The underlying complexity is being revealed, and that's progress," Valdes said.

At this point, vendors aren't aiming for full data portability, primarily because key technical and operational issues need to be worked out, as evidenced by the painstaking but valuable work being done by the Data Portability Workgroup, Valdes said.

However, vendors are comfortable offering data availability, letting their users expose content and data to other sites but keeping the data stored in their servers, he noted. "For the moment, until other issues are solved, data availability is the most pragmatic approach," Valdes said.

As outlined by proponents, the ideal data portability scenario would be for users to have full control over their social profile data, independent of any sites.