Aardvark

Google is on a shopping spree. In the last month alone, the search giant has snapped up SocialDeck, Angstro, and Slide -- all to help it take on rival Facebook.

Google has acquired Aardvark, a search startup founded by former Googlers, for a reported $50 million. Aardvark is a social-search engine that allows users to ask questions of their friends and friends' networks, and receive quick responses.