I don't know why Nick hasn't told us about his new book. I just found out
about it on his web site:
Anthropic Bias: Observation Selection Effects in Science and Philosophy
Nick Bostrom, Routledge, New York, July 2002
There are some free sample chapters at
http://www.anthropic-principle.com/book. I had to buy a copy of the book
because apparently only 6 libraries in the world has it, and none of them
are near me. If you want to buy one too you can use one of these links to
save $7 off the $70 list price. Each one can be used by only one person so
don't click on it if you're not going to buy the book.