Well excuse me if I only just noticed this (it seems like Google announced social search back in Oct) but this is simply the best innovation in Internet search in years.
Here’s what my search results included today when I searched for Knowledge Management:
What you can see here is personalised search results based on my social network as Google sees it. Google looks at your Twitter network, GMail contacts and profile links to figure this out. Strange it doesn’t seem to look at blogs I follow in Google Reader, but hopefully that will come soon.