Google has been experimenting with "social search" — which incorporates features such as showing when sites have been shared by your Twitter and Facebook contacts and letting you '+1' results you find useful — for much of this year. Like so many Google features, that option was initially US-only, but Google has now started rolling it out more broadly.
Google's newly-minted Inside Search blog notes that the social search features will be rolling out in the coming weeks, though the +1 feature might take a little longer. If you don't want Google mining through your email to suggest possible connections, we've got the lowdown on how to turn that feature off.
Social Search goes global [Inside Search]