Foamed Metal Heatsinks and Heat Exchangers
 

While this may look like sponge, what these panels and prototype heatsinks are made of is foamed metal, either copper or aluminum. The benefit of foamed metal is incredibly large surface areas, the downside is restricted airflow. High pressure fans are a must.

That look funny :)

and it's not even April 1st.....

same on overclockers.com

http://www.overclockers.com/articles1274/
http://www.overclockers.com/articles1278/
http://www.overclockers.com/articles1279/