There are a couple of websites showing the efforts of Christians and atheists trying out various churches.They observe how the church operates, the members and its community, sermons, etc. There have been a couple of books like I Sold My Soul on EBay by Hemant Mehta of Friendly Atheist and Joe and Casper Go To Church by Jim Henderson and Matt Casper of ChurchRater. These books are about non-believers attending a variety of churches and reporting about the experience.
Looking at various sites like ChurchRater, and reading the comments left there by various religious posters, I get the sense that Christians are very anxious for atheists to attend their churches. But I don't get any sense of the Christians wanting to reciprocate by attending any atheist meetings or events. I don't see any Christians actually attending an atheist or skeptic event. Perhaps this has happened, but it seems to be very rare.
I see atheists going to churches, Christian events, and talking with Christians and trying to understand them better. I see Christians talking about themselves with the atheists, and somewhat trying to understand atheists. Jim Henderson, an ex-pentecostal minister, seems like one of the few who actually listens to what an atheist has to say without having an underlying motive of trying to get the atheist to be Christian.
I'm skeptical of the motives of some of these Christians. Perhaps a few aren't in this to get converts and only want to meet new friends. I've had Christians approach me in friendship, only to loose them as friends the moment they find that I'm interested in learning about them, but have no interest in becoming one of them.
To me this whole business seems to be awfully one-sided. I live in the LA area, and regularly go to events at the Center for Inquiry West. What about any of you Christians out there? Are you willing to get to know us? I've gone to church with family and friends before to see what it's like, but have never had anyone ask to go with me to anything atheist or non-believer oriented.