Let me first say, that I don't like to bash religious beliefs unless they are perverse, violent, or threaten liberty. This does none of those, and quite frankly, I think it's a great idea, so please don't take this as disparaging, but there is something that really needs to be pointed out here.
Atheist 'mega-churches' take root across US, world
No, I'm not an atheist, far, far from it. However I've gotten into more than one argument with several different atheists who all claim that belief that there is no God, god, gods, etc isn't a religion. I'm really starting to laugh right now as remember those rather passioned discussions. Uhm...belief in something that can't be proven, is religion. Wait we can make that simpler, if you have to use "belief" to describe your position on something, that's religion.
Religion can be as complex or as simple as a man wishes it to be, because religion is man made. Understand that man made doesn't mean it isn't inspired by something outside of man, but man is the one who makes, and participates in religion by the beliefs he holds in his heart.
Every person has a religion. It's that simple. Each of us has things we believe that can't be proven, and the total sum of those beliefs is one's religion. On the minutia level, none of us share the same exact religion, but on a macro scale, when we share enough commonality a "religion" or "cult" or "denomination" etc is formed.
Atheism is the belief that there is no supernatural causation to time, space, and matter. It can't be proven, any more than the existence of any deity can be proven. And as one would expect, when a given belief reaches a certain critical mass, churches, or their rough equivalent emerge, where people come to worship something, and listen to someone teach about relevant topics.
So, in closing, if your an atheist, yes you do have a religion, just like every one else. It's not possible to not have a religion so long as your human.