It's part of social search: http://www.google.com/support/websearch/bin/answer.py?hl=en&answer=165228 http://www.google.com/support/websearch/bin/answer.py?hl=e

It's part of social search: http://www.google.com/support/websearch/bin/answer.py?hl=en&answer=165228 http://www.google.com/support/websearch/bin/answer.py?hl=en&... http://googleblog.blogspot.com/2009/10/introducing-google-social-search-i.html http://googleblog.blogspot.com/2009/10/introducing-google-so...