Since I've been an atheist, a few months, I've only openly shared with a few people my "beliefs". I don't think it's something that you can freely share without fear of something bad happening to you because of your beliefs. Do you or have you heard of any atheist stories gone wrong? What happened when you told a person. Well when I told my little sister over the phone she went crazy saying "That's crazy. How can you do that? That's wrong you grew up and church and have seen things." I responded "Oh really,, what have I seen that has proved to me that a God exist?", no answer.
I live in Texas and have had varied experiences, because I do sport bumper stickers, skeptical and political. That's why I'm not sure which one pisses people off the most here. Anyway, I have been egged, run off the road, approached in the grocery store, etc. I imagine my adrenaline level is usually off the charts if I'm in my vehicle. Otherwise, friends and family have all been very accepting.
I also must "confess" that we have a huge wall of crosses in our home which we call our wall of death. Even our religious family get a kick out of our "irreverance".
Peace and good luck.
I think there are many Atheist are are afraid of "coming out". I think the more Atheist "come out" the easier it will be for agnostics, and we will notice that more people that we thought are in fact atheist too. So tell everyone!