If you haven’t done so, check out and finetune your Google Profile, it’s listed at the bottom when someone googles your name. You’ll have a vanity URL, too. Here is mine: http://www.google.com/profiles/sebastiankeil
Also, released about ten days ago, Google now let’s you look at your social graph and what your contacts are sharing. This is the URL (you have to be logged in): http://www.google.com/s2/search/social#socialcircle
Interesting to see, how Google is not a social network but has all it would need in place…