The Sunon Waturbo isn't your average heatsink, at its center is a liquid core and a little magnetically coupled impeller to stir things up. As the 92mm fan spins, so do the blades of the internal impeller. This pumps the red glycol based coolant around the small aluminum chamber at the heart of the Waturbo, through a pyramid of 1mm square copper pins and around again. The idea is to use the liquid to distribute the heat from the hefty copper base to the rest of the aluminum heatsink. In practice, the concept more or less works.
FULL STORY @ FROSTYTECH (http://www.frostytech.com/articleview.cfm?articleID=2227)