Floating Ocean Windmills Designed to Generate More Power

"Researchers at the Massachusetts Institute of Technology and the National Renewable Energy Laboratory (NREL) have designed a wind turbine that can be attached to a floating platform. Long steel cables would tether the corners of the floating platform to a concrete-block or other mooring system on the ocean floor, like a high-tech ship anchor. The setup is called a "tension leg platform," or TLP, and would be cheaper than fixed towers."

http://www.scienceagogo.com/news/20060819023800data_trunc_sys.shtml