I don't believe in God. (Therefore, I am an atheist.)
I heard a podcast of KCRW's To the Point called The New Atheists. It's about how some Americans view a growing influence of religion in public life (primarily the creationist movement in schools, but also the anti-abortion movement and the perceived war on Christmas), and are responding with a more pro-active kind of atheism.
For example, Richard Dawkins has migrated from writing popular science (The Selfish Gene) to popular anti-religion (The God Delusion), and he's touring to promote it, including appearances on To the Point and The Colbert Report. (He did not appear on South Park, and didn't seem to mind except that they gave him a bad british accent.) He has referenced the Flying Spaghetti Monster, another popular anti-religion phenomenon.
Another of the To the Point guests was Penny Edgell, a sociology professor who contributed to a study about how religion creates community for the in-group, and at the same time discriminates against the out-group. Their findings (available at KCRW) revealed that as different religious groups become accepted in American culture (first Americans were Protestants only, then Catholics and Jews became ok), they exclude the non-religious, and they exclude atheists above any other group, including Muslims and homosexuals.
The paper is really interesting, especially the part where they interviewed people about "diversity in local contexts," and got commentary on atheists without prompting. They found that people view atheists either as immoral drug-addicted prostitutes or as money-driven materialists and cultural elitists. In either case, they're "self-interested individuals who are not concerned with the common good."
I think this goes without saying, but the above findings tell me maybe it needs to be said: Religion is not the only way to teach morals, and atheists are certainly not without them. Atheists are part of non-religious-based communities (neighborhoods, schools, etc.) and are often extremely concerned with the common good. Atheists generally don't organize (how do you organize around a common disbelief?), but several groups have popped up (or become more prominent) in recent years, such as Humanists, Freethinkers, Brights, Secularists, The Freedom From Religion Foundation, and The Center for Inquiry. *
Until now, atheists have been a quiet minority in American culture. Since it's not a racial or cultural distinction, and because religion and politics are off-limits in genial conversation, it's easy for an atheist to "pass" as a theist. I never considered that I might be "passing" by accident. (I'm not trying to hide anything, but I also don't have a Darwin fish on my bumper.) It's tough to wear your non-religion on your sleeve, mostly because some religies think it's their job to "save" you, but I think it's probably for the best.
So I'm coming out: I don't believe in God. Therefore, I am an atheist.
Now help me choose a logo.