I taught an English class in a hospital over here once, and on my way back through the offices, I was surprised at the number of Macs around. I was in heaven! G4s, B&W G3s and clam-shell iBooks all over the place!
It turns out doctors over here prefer Macs because of their high-res displays, or because of the software available.... I don't remember because I was drooling over all the hardware