Other Worlds: Space, Superspace and the Quantum Universe. By Paul Davies. Written for the layman. Not the most fascinating writing style but it covers interesting topics. For more info, go to Amazon.com and type in this ISBN #.
from the back of the book: Is this the only universe, or are there others? Is the world as we know it a random accident, or is it the outcome of a delicate selection process? ...Davies explores the astonishing implications of the quantum theory of the universe, in which particles can appear and disappear spontaneously, objects lose their individual identity, and the traditional understanding of reality must be completely revised.... Very heady stuff - fascinating though!!