I've been popping in to lurk for a couple of years, and finally decided to register! I hope I'll be a positive addition to the community.
I'm afraid I don't have a great "how I became an atheist" story. I was born not believing, and Italian mother and catholic school efforts notwithstanding, I never really saw any reason to start. I never really thought of myself as an atheist until college, when I was first exposed to evangelists, fundamentalists, witnesses, and other wing-nuts trying to push their screeds on me. That experience, I suppose, forced me to formalize my thinking on the subject. I've been an outspoken atheist and borderline anti-theist ever since.
Great to have you on the forum! Isn't funny how evangelists and fundamentalists bring out the atheist in most rational people, sometimes in liberal christians as well. I have to admit that it was exposure to these unsavory sorts when I first attended public schools that pushed me towards atheism.