Mammatus Clouds

Digg had a very nice link today to mammatus clouds. These clouds simly look amazing! As I've mentioned before I'm just nuts about clouds. When I saw the pictures of the mammatus clouds I took out my copy of the nice "The Book of Clouds" by Dr. John "Cloud Man" Day. Unfortunately the book didn't have very much to say about mammatus and neither has wikipedia. But the mammatus article at University of Illinois is OK. Gee, I wish I get a chance to see this kind of clouds for real some time.