I found this article in a Swedish Techpaper.
It is basicly a refrigerator without a compressor.
http://www.nyteknik.se/pub/pub27_3.asp?art_id=19074
Look at the picture and i will try to explain how it works.
The round disk, CD-size, has thermally isolated sectors. In each sector there is a insert of Gadolinium. Gadolinium is a metallic element that is magnetocalorific. Which means it heats up when it's put into a magnetic field.
When a sector goes into the magnetic field it heats up. The heat is transferred away to a radiator. When the sector exits the magnetic field it cools down to a temperature below ambient.
When this "cold" sector reaches the "thing" that is supposed to be chilled it takes the heat from the "thing" and gets warmer. The "thing" has now cooled down a bit and the, now warm, sector continues to the magnet to dump this heat. And so the cycle continues.
The positive side of this construction is that the only energy needed is to rotate the disc.