What about, still on the mini fridge idea, mounting the radiator for a water-cooling rig inside a mini fridge? If you took something like the ThermalTake Bigwater 745 and had one of the rads mounted in your case and the other in a mini-fridge would the mini-fridge be able to cope with that? Would the mf actually help the rad cool the water any further and would there be a noticeable drop in CPU/GPU temps?
Anyway, it's just a thought.
Anyway, it's just a thought.