Google has just launched a new search service based on social data: Google Social Search. It works like this: if you have a Google profile, you can add the social networks you’re a member of (e.g. Twitter or FriendFeed). Then, when you do a Google search, you will also get results that have to do with your friends, like a post from a friend’s blog. Of course, if you don’t add this information to your Google profile, or if you are not logged into your Google account when you do a search, you won’t get any social results.
Here’s a demo video of this new service. You might notice that Google is quite concerned about privacy issues, reassuring us about the transparency of the service throughout the video: