Google's Social API went public on Friday but didn't get much play in the news due to a certain company offering to buy another certain company.  Here's the official Google Post on it and here are some great posts by Dare Obasanjo and Tim O'Reilly.  I quote from the Google post itself...

So you've just built a totally sweet new social app and you can't wait for people to start using it, but there's a problem: when people join they don't have any friends on your site. They're lonely, and the experience isn't good because they can't use the app with people they know. You could ask them to search for and add all their friends, but you know that every other app is asking them to do the same thing and they're getting sick of it. Or they tried address book import, but that didn't totally work, because they don't even have all their friends' email addresses (especially if they only know them from another social networking site!). What's a developer to do?

One option is the new Social Graph API, which makes information about the public connections between people on the Web easily available and useful. You can make it easy for users to bring their existing social connections into a new website and as a result, users will spend less time rebuilding their social networks and more time giving your app the love it deserves.

Here's how it works: we crawl the Web to find publicly declared relationships between people's accounts, just like Google crawls the Web for links between pages. But instead of returning links to HTML documents, the API returns JSON data structures representing the social relationships we discovered from all the XFN and FOAF. When a user signs up for your app, you can use the API to remind them who they've said they're friends with on other sites and ask them if they want to be friends on your new site.

I don't really know what to say about this.  I'm not sure there's anyone out there who would argue against this idea and of all the companies in the world there's none better suited to execute it than Google. 

What is interesting will be how other Social Networking companies react to this news.  Allowing Google into your walled garden when it doesn't threaten you is one thing but allowing Google in when they are engineering a way to destroy your lock-in is quite another.  Especially when they own their own Social Networking site (Orkut) which will undoubtedly use this API to gain users. 

It seems like more than a coincidence that we didn't hear about this until after Google had made a deal to provide search data from Facebook.

For all the talk about Data Portability the reality is that Social Networks currently survive on their lock in.  They've literally bent themselves into a "pretzel of hypocrisy" trying to justify how they crawl other sites to get info but won't allow other sites to crawl them for that same info.  I can't imagine they're going to now lay down and let Google run away with that data. 

The question is whether they'll be able to do anything to stop it.  Once you open up its very hard to make the case for going back to a closed system.  Should be interesting to watch...

Addendum: For the record, I don't think Google is doing this for Orkut's sake.  Above I was portraying what a competitor would think not what my thoughts on the issue are. 

My opinion is that Google has become the public web in many ways.  It is the de facto portal to the web and as such it is the one company that benefits the most from the web being open.  So while I don't think Google is doing this for Orkut I do think they're trying to open up Social Networks to benefit from it. 

I don't think it matters if you use Orkut or another network they just want to open it up completely.  Because when the social networks are open completely they become just another part of the web and Google is, as mentioned above, the de facto portal to the Web.