I found a great book out there called the Atheist's Bible. The entire contents are quotes, mostly atheists or agnostics but also from critics of organized religion. The book, edited by Joan Konner (former Dean of the Columbia Graduate School of Journalism), contains quotes covering everyone from Richard Dawkins and Sam Harris to Gypsy Rose Lee, Homer Simpson and Woody Allen. For any Atheist this is a great book to keep handy. Dont let the title of this one scare you off, The Atheist's bible is humorous, inspiring and just plain insightful.
A book of quotes? Jesus, that sounds like a waste of money to me. I just LOVE random sites you find when you search for "Atheistic Qoutes".