I agree with everything that Paul Hallas has said. Peek Performances is a brilliant book provided that it is read properly and not treated the way many magic books are. That is to say that it is skimmed through and only the few bits that may look interesting are read followed by throwing the book on the shelve, never to be looked through again except to impress visitors to their extensive library.
What Mike Close failed to appreciate was that in Mr. Busch's opening remarks in his forward, he explains that the book is written in a specific manner geared to aid in the learning of the material within but that to gain all the reader can, they must read from chapter to chapter (after grasping the earlier concepts) as each chapter builds upon what was learned in the previous ones.
If you want to develop your skills in the art of the peek, be it magician or mentalist, then this book is the ultimate in mastering this skill. If you prefer to learn your magic piecemeal or from videos alone, don't bother.
Paul Alberstat http://www.bigfoot.com/~thoughtreader