I've "dreamed" of having this, mainly for the quiet-ness rather than for the OC potential. Having those fans running all the time is a bit annoying, sure most of the time music or games drown out the fans, but when I'm just typing it's hard to ignore.  
 
I think I'm too lazy to read up on how to do it, and it seems like a small risk. So who here is using this instead of regular old fans to cool their systems, what has your experience been like? Any tips? 
 
Edit: If I'm not mistaken, you do need at least one fan even with liquid cooling.

I'm using it, check my image uploads if you want to take a peek (they're also in the share your rig thread).
 
Water cooling these days is a lot more simple than it used to be, gone are the days of pulling heater cores out of old cars for use as a radiator.
 
Generally though if your not looking for overclocking potential and simply silence your best bet is to pick a decent tower cooler and whack a nice quite 120mm fan on it, you will get sweet performance and the same noise levels (in some cases less if your water pump isn't insulated properly and is causing large amounts of chassis hum).  Installing water cooling is quite time consuming and (measuring all your hose length's, leak testing etc).  It's also quite expensive and really isn't worth the price of entry unless your going to pushing out 4ghz 24/7.
 
My advise is to pick up say a Thermalright True 120 and then couple it with a good quality 120mm fan running at say 5v to keep the noise down.  The Cogage True Spirit is another great option if money is tight.

Here, but only on my CPU. Will be upgrading to more robust watercooling system next year when I get new graphics cards. 

my car is.

I will eventually. Right now I gotta get a new tower to show off the water cooling when I get it.

me

I will be when my Alienware Aurora arrives.