Facebook announced "Facebook Connect", which they position as the natural evolution of Facebook as an open platform, which started from their initial API in 2006 and expanded with Facebook Platform in May 2007. This is how they describe Facebook Connect:

"Facebook Connect is the next iteration of Facebook Platform that allows users to "connect" their Facebook identity, friends and privacy to any site. This will now enable third party websites to implement and offer even more features of Facebook Platform off of Facebook – similar to features available to third party applications today on Facebook."

Overall, this means that all of the fun stuff that developers are building into apps on Facebook Platform will now be available for third-party developers to build into applications OFF of Facebook.com.

I spoke with Ben Ling at Facebook, and the hypothetical example he used was yelp.com. If I link my Facebook identity to my Yelp identity, I'll be able to port over my profile, my content, my reviews. Also, I'll be able to see if any my Facebook friends are also members of Yelp -- and be able to automatically have our friendships authenticated and visible on Yelp.

This is the beginning of the future I laid out earlier this spring, where social networks will be like air -- everywhere you need and want them to be. Facebook has a distinct advantage in this space, given its vibrant member base AND its relationships with developers who are already creating these social apps. Ben gave me some startling numbers: 24,000 Facebook applications, 350,000 developers on Facebook Platform, and 70 million Facebook users who have installed an app.

So in a few weeks, we can expect to see Facebook leaving the confines of its server, allowing users to take their Facebook experience anywhere they want. Instead of damaging itself and eroding the value proposition, Facebook is extending the reach of its social network through the Web.

With Yahoo! Open announcing and MySpace in the data portability game, it's now a battle not for just users, but a race to see who can open faster -- and more importantly, play well with other sites. Remember Facebook Beacon? That was an innovative program with partner details not very well thought out or implemented. I don't expect Facebook to make the same mistakes and if anything, they are ahead of the game having learned from that painful experience.

I did ask Ben about the timing of the announcement, coming as it does on the heels of MySpace announcing that it was joining the Data Portability Project. He said, "Openness is part of our DNA, We want to be transparent about our intentions, about the type of functionality we will offer to developers. There is a lot of mistaken perception that we are a close community."

So welcome to the race -- and look for a lot of interesting things to happen as the giants in this space - MySpace, Facebook, Yahoo!, Google, Microsoft -- all try to outdo each other in connecting with other sites. I for one am very much looking forward to it -- good bye social silos!

What "dream applications" would like to see developers build in this brave new world of social networks being extended into other sites? And what concerns do you have, especially if you work on a site that could be linked to these social networks? Let me know in the comments below or email them to me at cli at forrester dot com.