Apparently, it has something to do with a secret society who investigate the relationship between Jesus and Mary. Or something like that. All I know is religious groups are up in arms about it and were petitioning against the films release. I know I've got to be one of the few left in the country who has not seen it and don't plan on it.
I really love the book and when I heard that they turned it into a movie I was looking forward to it. Then I read the critics and they pretty much said what TonyTony says: Nothing exiting, rather disappointing and not really worth the money.
A great storyline, excellent actors - how could they mess that one up...