http://autos.yahoo.com/blogs/motoramic/wind-powered-blackbird-sale-rewriting-physics-134230233.html

Rick Cavallaro has been called an idiot more times than he cares to remember. After posing the theory that a wind-powered vehicle can travel downwind faster than the wind, negating centuries of scientific belief, the Internet and its readers pointed, laughed and ridiculed the mad scientist. But on July 3, 2010, Cavarallo and his cronies silenced the doubters by constructing a wind-powered vehicle that travelled close to three times faster than the wind itself.

This guy did it downwind... I have always thought one had to go faster than the wind using a vector angle, on some sort of reach.