One good thing that The Da Vinci Code did inspire was the book "Truth and Fiction in The Da Vinci Code" by Bart Ehrman. It is the best introduction to the basics of New Testament scholarship that I have seen by who is perhaps the top scholar in the field, and it is a quick, easy read. Basically, Dan Brown's chief source for the book (right down to the use of secret societies) is "Holy Blood, Holy Grail," a book that is universally derided by Biblical scholars and considered a work of pseudohistory. The book walks through each point of BS in The Da Vinci Code and then clarifies what really happened or what was a total fabrication.