Ring of Fire Enterprises
Offers Darwin fish symbols and other anti-religious products.
http://www.rof.com/

Reasonworks.com
Offers freethought audio tapes.
http://www.reasonworks.com/

Darwinfish.com
Car plaque, bumper stickers, buttons, t-shirts, decals, and posters. Ordering information, wholesale, and catalog.
http://www.darwinfish.com/

Prometheus Books
Independent publisher of books, journals, and audio tapes for educational, professional, scientific, library, popular, and consumer markets. Their selection includes a number of atheist, humanist, freethought, and skeptic books.
http://www.prometheusbooks.com/

Atheists Online
T-shirts, sacriligious sweatshirts, infidel jerseys, heretic hats and blasphemous bumper stickers.
http://www.atheists-online.com/

Yo-God.com
Sells Yo-God God detectors, available in standard and deluxe versions.
http://www.yo-god.com/

The Theory of Reality
Atheist book my Samuel Tolsdorf.
http://www.tolsdorf.net/