PC cooling systems are one of the hottest - and coolest - computer hardware accessories avaliable. Most computers, however, still do not come with a cooling system more advanced than the typical heat sink and cpu fan. Some computers, however, are being sold with liquid cooling systems, such as the Apple G5 Power Mac. The dual processors undoubtedly put out a great deal of excess heat that a simple copper heat sink and fan alone can not properly dissipate. Intel is also getting into the new cooli.