http://www.popularmechanics.com/blogs/science_news/4235579.html
QuoteThe towers utilized the Magnus effect—wind currents striking a rotating cylinder exert a force approximately at right angles to the direction of the wind. After an initial jumpstart from the motors, the cylinder's motion caused the ship to advance, PM reported. Its designers claimed the vessel outran other sailing ships as well as freight steamers.
http://en.wikipedia.org/wiki/Magnus_effect
(http://upload.wikimedia.org/wikipedia/en/thumb/1/15/Magnus_effect.svg/350px-Magnus_effect.svg.png)
http://www.boatdesign.net/forums/boat-design/everything-old-new-again-flettner-rotor-ship-launched-24081.html
QuoteOn the New Orleans-Jamaica route, where winds are usually unfavorable, the fuel savings was an incredible 36 percent, and the speed was up 18 percent. If the ship were used on similarly favorable routes, the payback would fall to an astonishing 1.7 years. "
http://en.wikipedia.org/wiki/Flettner_ship
QuoteStephen H. Salter and John Latham recently proposed the building of 1500 robotic rotor-ships to mitigate global warming. The ships would spray seawater into the air to effect Cloud reflectivity enhancement.[1][2]
I would never havve thought of that.
Science is fun! :D