To celebrate the Web's 40th anniversary, DARPA wants to explore social networking's role in time-critical communication. It's offering $40,000 in hard cash to the first entrant who finds ten 8-foot weather balloons located at fixed locations around the U.S.

Registration begins on December 1, and the balloons will appear on December 5. The first to submit the latitude and longitude of all ten balloons walks away with the cash. Pretty cool. Full rules at: [DARPA via BoingBoing]