In one of the best mainstream explanation of the errors of The Da Vinci Code, the AP of all people get the facts out. And it's not just the right-wingers who see the problems in Brown's book/movie:
Among more liberal thinkers, Harold Attridge, dean of Yale's Divinity School, says Brown has "wildly misinterpreted" early Christianity. Ehrman details Brown's "numerous mistakes" in "Truth and Fiction in the Da Vinci Code" and asks: "Why didn't he simply get his facts straight?"
Because one doesn't want the facts to get in the way of a good story, of course.
The article really is a strikingly balanced by explaining straightforwardly why scholars have problems with Brown's claims regarding the divinity of Jesus, the Biblical canon and the marital status of Jesus. It would probably be worth printing out and having handy when your iconoclastic friends come over.