Savagely funny, this biting satire is set in the port city of Guayaquil and the Galapagos. Its narrator looks back from the future on the "nature cruise of the century," where he and fellow passengers improbably survive the extinction of the human race. We're guessing that Vonnegut was inspired by a cruise to the islands. Completely loony, this fast-reading novel is great fun to read after a visit to the Galapagos -- when you can thrill at recognizing Vonnegut's source material.  (GPS10, $14.00)