The guys from Puget Custom Computers wrote a howto on submerging your PC into mineral oil. This looks very cool and allows you to make your PC almost completely noiseless.
The mineral oil aquarium alone had an incredible ability to absorb heat into the oil, and for that reason, this is a great setup for periods of load less than 12 hours long. As long as you give it some cool down time, it runs some great temperatures. We do want to stress that at no time was the system unstable, ever....which was surprising! It doesn't seem too much a stretch to expect that you wouldn't put a typical computer under load for more than 12 hours...after all, even gamers have to sleep! With that taken into account, this setup as it is could serve as a great, eye catching way to cooling your computer.