The thing about dry ice that makes it an efficient solid coolant is not the passive conduction of heat, but the forced intake of heat in the endothermic process of sublimation. As the ice sublimes, (as it must at room temperature) it absorbs heat from the surroundings, and this absorbing is not "take what I get", but "grab what I can". It really is a vicious uptake of heat. If you were to drip water on dry ice, the water would freeze, because heat is "sucked away" from the water for sublimation to occur.

If you put dry ice on metal, the dry ice will definitely cool the metal down by absorbing heat. The rate of heat absorbed depends on how much surface area there is, as well as the latent heat of the dry ice. Drawing air over the dry ice is not as effective, because that air saturated with freshly-sublimed carbon dioxide is warmer than the dry ice itself, but still cooled by it anyway. However, only the air in the immediate atomic area that passes over the dry ice will be well cooled to below zero degrees; air passed over a centimeter away will be rather warmer, and air passed over an inch away mightas well have been normal cool air conditioning. It's all about surface area here. Note that air is an extremely poor conductor, so it will be the limiting factor, not your dry ice.

Note: moisture may condense into tiny droplets or even freeze into minute crystals when it passes over the dry ice. If it settles on the circuits in large amounts, you're asking for trouble though I don't think it will be a matter if you're not in a place with 100% humidity like me.

Besides, I once tried to supercool my processor, and the lowest it would go was 32 degrees. it either refused to go lower, or my thermistor can't record it.

When working with dry ice, always use gloves (the heat "sucking" can freeze your skin off, theoretically, if you touch it long enough), and be in a well ventliated room with windows open. If you feel breathless, or notice a big increase in rate of breathing, scram immediately, because that's the increased carbon dioxide level in your blood that triggers the breathing process to accelerate.

Perhaps we could miniaturize the good old fridge compressor and run it directly through the heatsink on the cpu. Better yet, insulate the tower and shill the inside to about 4C, you could probably fit a door on the side of the tower and keep a couple beers cold in there.

Off to the patent office,
Ripcat

just drill a hole in the side of your freezer for cables and stick your CPU in there.

Give us some pictures of that dry-ice-in-a-puta, will you

Yeah, the news broke, alright.
Why can't news be reported whole? As in, a nice, full, story, not "details soon!" and advertisments?.

*Sits at television waiting for "details"*