it's also called a TEC (ThermoElectric Conductor). go read about them on overclockers.com.
There is a Swiftech heatsink that ships with a 226w peltier (
MCX462+T), but its performance doesn't warrant the headache peltiers cause. I've used TECs in 3 separate water-cooling loops, and when they work they way they're supposed to, you can get sub-zero CPU temperatures; but in the end they are just a pain in the ass, either because of the brittle wires, or having to power them with a separate supply, or preventing condensation from shorting your board.
more info can be found in the cooling forums at short-media.com and xtremesystems.org