While I'm shirking my blogging responsibilities by linking to series of posts elsewhere, there's an interesting discussion about hostility to atheists at the Volokh Conspiracy: see here, here, here, and here. You'd be unsurprised (I suspect) to learn that Americans find atheists to be one of the most untrustworthy brands of people around. Just to get an idea, here are the answers from a 2005 poll that asked whether "your overall opinion of [the group] is very favorable, mostly favorable, mostly unfavorable, or very unfavorable?"
Group
Very favorable (%)
Mostly favorable