Undergraduate-friendly reading material on the multiverse? I'll be teaching a seminar for first-year undergraduates next year. The idea of my university's first-year seminar program is to expose students to exciting ideas and important texts in a somewhat interdisciplinary way. My course will focus on three epochs in the history of cosmology in which our ideas about the size of the Universe underwent radical expansions: the Copernican revolution, the early 20th century, and the present / recent past. 
I have a lot of ideas for good undergraduate-friendly readings on the first two topics, but not so many for the last one. One idea I want to get at with them is that recent theories suggest that the observable Universe is a small and perhaps not even typical fraction of the entire Universe. I'd even love to get them arguing about the anthropic principle while I'm at it.
So my question is this: Can you suggest good books, articles, etc. for me to consider in the syllabus for this course? Because of the interdisciplinary nature of the course, I'm happy to consider fiction, philosophy, and history as well as straight-up science. (For instance, Borges's story about the Library of Babel has a nice metaphorical connection to some of these ideas.) Just remember that these are kids fresh out of high school -- they're not ready for Phys. Rev. D!
 A: On January 25th, Brian Greene will release his 3rd popular book, The Hidden Reality,

http://motls.blogspot.com/2011/01/brian-greene-hidden-reality.html

which is dedicated to the multiverse. A counterpart of the book by Lenny Susskind is The Cosmic Landscape,

http://www.amazon.com/Cosmic-Landscape-String-Illusion-Intelligent/dp/0316013331/ref=sr_1_1?s=books&ie=UTF8&qid=1295369061&sr=1-1

You may also select some review-like preprints on the arXiv - to choose randomly, Vilenkin and Garriga

http://arxiv.org/PS_cache/arxiv/pdf/0711/0711.2559v3.pdf

Try to find many papers e.g. in this way:

http://scholar.google.com/scholar?q=multiverse+anthropic

A secret feature of all these papers is that they're not difficult at all and undergrads can get them. It's pretty much philosophy and most people feel very self-confident that they have something to say about these issues, and in some cases, they're even right.
A: Probably David Deutch's Fabric of Reality.  He pretty much wrote the book on the multi-verse and is very accessible.
