As mega-websites continue to throw their support behind Google's OpenSocial product aimed at breaking down barriers across the net, at least one serious player is still very much out in the cold. Billed as a serious threat to Facebook, OpenSocial appears to be the latest flashpoint between Google and the social networking wunderkind.

According to a TechCrunch report, there is a dispute over whether Google briefed Facebook on OpenSocial. At a press conference yesterday, Google said it had briefed Facebook, which saw rival MySpace join forces with the search giant late in the day. But officials at Facebook told the tech blog that no such invitation had been extended.

"Despite reports, Facebook has still not been briefed on OpenSocial," Facebook said in a statement. "When we have had a chance to understand the technology, then Facebook will evaluate participation relative to the benefits to its 50 million users and 100,000 platform developers."

Michael Arrington, who reported the story for TechCrunch, called the move a "coup" for Google, pointing out that the avalanche of support the company has lined up for OpenSocial will likely force Facebook to join.

Tensions between the two companies surfaced when Microsoft announced a $240 million investment in Facebook late last month. Google had long been rumored as an interested investor, despite the fact that Microsoft sells the bulk of Facebook's display advertising.