EVGA is showing their Nvidia 680i motherboard at CeBIT. The board has one unique feature that sets it apart: it is meant for a completely fanless installation. It comes with cooling blocks mounted on the Processor, north bridge and south bridge as well as the power regulation area. As long as you don’t throw in some monster video card with a fan, there is no need for a fan at all.
The typical use for a silent installation is in a room that is not meant as a computer room only, like in an HTPC situation where it is in the living room. But I have to say that I am getting tired of listening to whining fans everywhere I have a PC. Technology is beyond that, and the noise just annoys me. Call me a pansy if you must, but I would take the cost and nuisance of setting up water cooling to escape that noise anyday.