I went to see Religulous with my brother this weekend. It is clearly a Fahrenheit 911 for a discussion of the role of religion in our lives. By that, I mean it kind of touches on some real issues, but is mostly a fun movie for those who think religion is evil. As someone who links many aspects of the religious establishment are evil, it was a a mixed bag.
A better source of real examination is Sam Harris's End of Faith.
I think both of these works have a couple of faults. First, they reject the notion that religion can be used as a justification for violence that would happen without religion, and seem to ignore secular violence all together. Second, they focus on violent, close-minded adherents and consider more thoughtful adherents to be less Muslim, or less Christian or less Jewish. (FYI, Harris addresses these complaints, particularly the first, I just wasn't convinced.) Bill Maher also trivializes the role religion plays in people's lives. Harris, on the other hand, recognizes that humans do have spiritual needs. However, both suggest the cost of religion is not worth the benefit.
This is a real question for me. Those with a simple message often seem more excited about their faith than those of us with a more subtle view. Also, no matter what fraction of Christians believe in the Rapture, Creationism, or other non-Biblical constructs of recent years, is there any question about whether those Christians have had the loudest voice in the political discussion?