I know only three atheists personally.
Two of them were raised completely devoid of any religion -- no church, no Sunday school, no religious brainwashing whatsoever. These two agree with almost everything posted on this site, but would never care enough to actually join an atheist site. They didn't know of Hitch, Harris, Dawkins, PZ etc. until I introduced them.
The other one, like myself, was raised to be christian. He went to catholic schools through high school. I was forced to church 1 to 3 times per week. I then went on to a christian (church of god) university (for proximity reasons). Other than having to go to chapel every Tues & Thur morning (until I found a way out) and my world history professor being forced (against her will) to skip the section on evolution -- I found it to be a very good education. My required bible classes forced me to look at the bible in a different way than the church had. This started me on the road to my present, very happy, atheist state.
I notice that my catholic-raised friend and I are both active atheists in contrast to the other two. Has anyone else noticed a correlation between your degree of religious upbringing and your zeal for (1) the active search for scientific truth and (2) the defense of the value of evidence and skepticism?