First...watch Sam Harris' TED Talk from earlier this year: http://video.ted.com/assets/player/swf/EmbedPlayer.swf
I've been ruminating on it ever since he gave it. I went through all sorts of emotions when I watched it. Some anger and dismissal, but also some a-ha moments. His argument is, basically, there is a right and wrong morality (and some grey areas) and that science, not religion, can help us determine. And the determination is to maximize the human condition. His talk is worth watching and discussing and Chris Anderson asks some compelling questions at the end.
Ironically, it is the recent debates in the US over healthcare and the subsequent BP Oil Spill (both failures of science) that has got me thinking about this talk again. I've gotten to the point where I don't think it's healthy for us to be tolerant of values that infringe on the lives of others for personal gain. And I don't know if science is the answer, but I'm willing to support the pursuit of finding out what maximizing the human condition means and how we can get there.