Bing now uses ‘Facebook like’ to used to improve search results. When you search for a keyword in Bing, other than the normal search results, Bing also gets to you results of the keyword “liked” by your friends in facebook. This would help us in not just searching but also making decisions based on what our friends feel about the product or service. Indeed a great feature. But remember to integrate Bing with your Facebook. Danny Sullivan has detailed information for you.