This book is a collection of ideas for unconventional photography. I would have given it five stars but 80% of the ideas require an SLR (and a lens or two that need modification) which means they're useless for the casual photographer.
Some of the ideas are more interesting than others. There's a tutorial on using your SLR like a microscope and turning it into a telescope (both require SLR and a modified lens) which I thought sounded pretty cool. But there's also a section on lighting which while it may be useful, is not exactly unconventional photography.
If you have a SLR camera and are looking for a new project, I highly recommend this book.