Being a Limey, i've never actually heard of WaterWetter. I don't think it's available over here yet, but i don't know of any Brits with water cooled pc's. I have no plans for any water cooling, but i was looking at the peltier things, and they look very interesting. Certainly seems like a more efficient and safer way to cool the chip, and it saves having to hire a plumber to check up on your computer. If you get an airlock, it'll certainly spell disaster.
With those peltier things, does the actual peltier need to be cooled as well? or can you just strap the unit to the cpu? it would save a lot of noise anyway.