im thinking about getting a water cooling system pretty soon, i spose what people worry about and what they've been brought up thinking is ELECTRICITY + WATER = BAD, i know i have, but i think if/when water cooling comes into the mainstream (and i dont think it will do) it will become pretty normal to buy completely silent PC's that are water cooled, although i think Fans will play the primary role of cooling for a few years yet, saying that tho, cooling with heatsinks and fans is such an old technology i think there should deffinately be some kind of breakthrough by now in cooling, either that or cooler CPU's.
Toms Hardware had the right idea, Liquid Nitrogen is the future!! :grinthumb