Off the wall at Callahan's is a collection of all the best sayings that Mike Callahan collected over the years, some of the worst puns, and the nicest songs. There is also a short foreword by Spider explaining how this book came to be, and an section at the end listing the person who appeared over the various books in the Callahan's Saloon series. The book also features several cute interior illustrations by Phil Foglio, and is printed on acid-free paper (according to the jacket). While this book is NOT a collection of stories as are all the other books in this series, it DOES give valuable background and interesting tidbits. It's probably not a good book to get if you've not read any of the rest of the series, but if you have and liked them, it'll probably appeal to your taste. I liked this book very much myself, but could see where it might not appeal to non Robinson fans.