If you dont want to run standard water or distilled water, have a look at this.
[url="http://www.inertx.com/"]InertX[/url]
It is a coolant that is non conductive, so if there was a leak inside your PC whilst it was turned on, there would not be a problem. It dries incredibly quickly, its UV stable, no gunge can form in it.
I use it and love it!
I have to say, I prefer external solutions to water cooling, easier to maintain.
I use the Koolance EXOS cooling system.
[img]http://www.pcs-norwich.co.uk/postpics/lidofflight.jpg[/img]
[img]http://www.pcs-norwich.co.uk/postpics/lidoffdark.jpg[/img]
