This book is hilarious, with lots of quotes from the Discworld series. I've not read all the books yet, and some of the book that I have read, I would have included some other quotes, and left out others. But as the author said in the preface, this is his personal favourite and is by no means exhaustive.
There's not much to say about this book, since it's aimed more at fantasy/Terry Pratchet lovers. However, I think it's an infectious book, that can amuse all those wanting a laugh. Case in point, my friend borrowed this book almost as soon as I finished it. I guess the quotes really do speak to people. Either that, or there are Terry Pratchet fans everywhere.
Before I forget, here's the amazon link: http://www.amazon.com/Wit-Wisdom-Discworld-Terry-Pratchett/dp/B002QGSXXC/ref=sr_1_1?ie=UTF8&s=books&qid=1289562480&sr=8-1