if we could reach absolute zero it'd stop working, suggest flooding it with Liquid Helium, coldest thing we've got at Uni, and a good bit colder than pluto too, Liquid Helium is something silly like 4 kelvin
I've seen a Liquid Nitrogen cooler, they look crazy. Lol.
On another note, Intel have created a transister that can flip at about 20 billion times a second (I think). I am not too sure on the exact speed it can alternate at but it's about that. Check http://www.intel.com For more infomation.
i saw on a website once these guys got a 486 to ~230mhz with extreeeeeeeeeeeeeeeeeme cooling... it ran half-life, slowish but it ran... 5 mins later they had one very fried 486