About halfway through, I realized I'd read this story before, namely in Umberto Eco's Foucault's Pendulum. Eco's book pre-dates Brown's by more than a decade, and Eco's writing (translated into English) is both rich and dense, requiring skill and thought to appreciate, much like a high-end chocolate confection. I'll admit to not finishing Foucault's Pendulum because my reading pace didn't allow me to made adequate progress through the book, and eventually the wear and tear from toting it aboard airplanes beat the book before I did. It's a shame my copy didn't get frequent flyer miles or I could have sent it to Hawaii for free.
I'm far from the first person to recognize or react to the similarities; google "davinci code foucault's pendulum" and you're greeted with a rash of conspiracy theorists and their rankings worthy of amazon.com content.
The DaVinci Code is to Foucault's Pendulum as West Side Story is to Romeo and Juliet. That should suffice to upset nearly all literati, trade fiction readers, and Jets fans everywhere (who are already worried, but that's another story). But -- I liked the book. I finished it in two days. I figured out how to carry it with me while hobbling on crutches, which is something that I can't say for my laptop, the town newspaper, or even the most recent ESPN: The Magazine.
By making secret societies and various shades of mythology accessible to the general reading public, Dan Brown scored a lot of points, measured by weeks on the bestseller lists. There's a lesson here for technologists -- accessibility counts. If it's hard to figure out, only a few will bother. Simple wins.
Have you heard about this dollar per CPU-hour utility we're building? Simple wins, and it's accessible. Sorry, commercial message in the middle of an itinerant literate rant.