This post on the Friendly Atheist made me think, particularly about myth #3, "atheists are aggressive and rude." It would be nice if we could keep discourse between Christians and atheists civil and courteous, but the truth is that's not too likely.
Here's why. The atheist position (no matter how kindly stated) boils down to this: "Religion is false." When a religion constitutes someone's most cherished beliefs, s/he is bound to see that as an insult.
The Christian position, on the flip side, is, "Atheists are going to hell because they don't believe in god." Certainly not every Christian believes this (liberal Christians may not even believe in hell), but many do. There's no way to put that really politely, either.
So we can strive for courtesy, but odds are, Christians will perceive us as rude no matter what. And odds are, the conversation between Christians and atheists will always be marked by a certain rancor.