UberBong: Evaporative PC cooling, probably
 

Performance :: Keeps CPU @ ambient, water temperature 6°F below ambient, fans optional with such high water flow.
Smaller CPU pump + flow restriction valve on bong pump to aid in achieving maximum cooling.
Currently evaporative cooler actually lowers room temperature.

http://www.ku74.net/uberbong/

News is already couple years old, saw it in 2005 for the first time but it wasn't new back then already. Nevertheless one of the best pc-bongs ever made, I don't think anyone is still experimenting with this kind of cooling though. Had my own bong couple years ago, no great succes, crucial factor might be the evaporator I guess.