I had a great idea! In another discussion someone mentioned secret handshakes or a way to tell who in the business world is an atheist. How about instead of using the '@' symbol for you email address, you instead replace the '@' with Dawkin's scarlet letter 'A'?
It's discrete, if they don't know what that symbol means they'll think you just went out of your way to make the at symbol look creative. If they recognize it... think of the possibilities! An entire network of atheists in the business arena!