First of all, Joe and Kalhoun, do you want to hear something REALLY amazing and unbelievable?
I was NOT an atheist when I came into AA 16 years ago.
I am not bullshitting you, dudes! I was not exactly a Christian but I believed that some God was listening to my prayers.
I actually became a declared atheist over the years as a result of reading various materials and thinking for myself. All the while attending AA meetings on average twice a week for 16 years (do the math). So if AA brainwashes people into believing in God, they sure do suck at it! 
By the way, I am a popular as a speaker at meetings. At some meetings we share individually each saying what he wants for 5 minutes or so. And at other meetings called “speaker meetings” (these are the ones that are open to non-alcoholics) one person gets up and speaks about his life and experiences. I regularly mention that I have become an atheist over the years. I have yet to see anyone be bothered by this in my audience. And if they are bothered, the traditions of AA clearly say that is their problem and they have no right to correct me or give me advice.
All an atheist like me has to do to go to AA and remain sucessfully sober for 16 years now is to be tolerant of the fact that other people may think other ways, that other people see their higher power as God, or Allah or Jesus or whatever.
Evil Joe asked to whom do I pray? Good question. Reminds me of the atheist whose tombstone said “All dressed up and no place to go.” 
By the way, if you look at anotgher thread I started in GD, I clearly say that intercessory prayer has no power to change anything. In other words, there does not appear to be some great God out there who listens to our pleadings and cures grandma’s tumour.
What I do is a form of atheist prayer-like/meditation, every day. One of the major slogans in AA is “Think, Think, Think”. I would no more want to go without my daily meditation than without my daily shower or my daily crap.
It does not matter if anyone is listening “up there”. My gut instinct is that there is NOT anyone listening, which is why I am an atheist. But do you know something? I am not omniscient. There may be some power out there that is radically different from the ridiculous vengeful God of Christianity who gets his own son nailed up because he is offended by what humanity does, and who drowns millions of innocent children in a world-wide flood.
My belief in God is like my belief in Bigfoot. I am pretty sure there is no giant, apre-like humaoid living in the Pacific Northwest. And I would be astounded if anyone ever actually found one or cpatured one. But my mind is not 100% decided on the matter. It is 99% decided. The other 1% is there in case someone brings me some evidence that I can accept, someday.
But don’t get me wrong. My use of my prayer-like meditation is NOT founded on that 1%. It is because of what a quiet time of meditation and contemplation does to and for ME. That is why it does not matter a whit if no God is out there listening.
Take the famous “serenity prayer”. When I meditate I say “May I have the serenity to accept the things I cannot change, courage to change the things I can, and wisdom to know the difference.” Other people say “God grant me the serenity. . . .”
I sometimes meditate ten or fifeteen minutes a day on the serenity “prayer”. Theists see it as something that God grants, and I see it as something that I acquire. It makes no difference!
What makes a difference, and where all the benefit lies, is in each day, delving deeper and deeper into what is meant by those words, and applying them to myself. It is impossible to explain meditation. You have to try it.