Extreme Mammals

The American Museum of Natural History has an exhibit called Extreme Mammals running from May 16, 2009 through January 3, 2010 that "explores the surprising and sometimes bizarre world of extinct and living mammals" ranging from the egg-laying platypus to the "walking whale" Ambulocetus to the six-tusked Uintatherium to the largest known land mammal Indricotherium.

It sounds like a unique show to see.