Normally when I do a vanity search, I use my full name. Today I did a search for just "Andy" for fun. I wasn't expecting this:
At first I though Google Search was broken. How could this story about me be on the first page of search results for "Andy"? Then I realized I was looking at a new feature, called Google Social Circle.
It's quite ingenious actually. While Facebook and Twitter are first building a social network and then building (or in some cases hacking) search on top of it, Google is approaching the problem of social search from the opposite direction. They've built a rock solid search engine, and now they're experimenting with the social side of search. I think it boils down to this: people are going to be more likely to visit a link that is recommended, written by, or is in some way associated with one of their friends.
Disclaimer: I work at Google (on unrelated projects).