I read Digital Fortress a few years ago. Aside from a rather shaggy dog plot, Mr. Brown after whatever great research chose to change the laws of physics as a plot device. Nice going.
I did not read Da Vinci Code so much as listen to a books on tape version of it while I was driving across the country in late '04 and camping in campgrounds left empty by the cold. It was a nice diversion, but a crappy book. Also a shaggy dog's tale ;-).
I do own a "Da Vinci Cod" T-Shirt by Alaskan artist Ray Troll. It rocks.
I don't know much about 'masons and mormons but I own a Congress Of Wonders album featuring The Stoned Ranger where he saves a wagon train of folks of the Mammon Sect led by Gettum Young.