I dunno, I've attended the local UU church here a few times and if I was an atheist it'd be the last place I'd want to be. From what I remember of the church services, one went something like: some chit chat, something about Native American spirituality from a Native American fellow, a couple songs from the Protestant hymnal, some time to share what was going on in your life, another Protestant hymn, a sermon for 15 minutes about how the Bible has errors but the New Testament is a great basis for morality, how we can learn a lot from Buddhism, and other such things, a final Protestant hymn, then closing stuff. That was followed by coffee time and some very light discussion. I suppose if I considered myself "spiritual" or wanted to socialize it'd be a fine place. But as either an atheist or traditional Christian it didn't seem to have much to offer.