By using the social networks you have claimed in via Google Profiles and your Gmail account, you can see comments, photos and connections from your network using a new labs project called Google Social Search.
In this video, demos Google Social Search and compares it to the current search capabilities of Google.
Bottom line: If you include your social networks (FriendFeed, Twitter, Picasa, Blogger, etc) in your Google profile, you are giving Google permission to index that information for your Google Social Search results. At this time, Facebook is not included.
You can access this experimental project and others here.