Here's a T-shirt available on Richard Dawkins' web site:
The bit at the bottom is text on the back of the T-shirt. I like the way it makes the choice pretty stark. You can decide to throw your lot in with those who read the text of a 3,000 tribe of nomads with tales gathered from the civilizations around them and their own half-remembered history. Or you can go with modern science which is a democratic, experiment-based, rational methodology for discovering facts and building theories. In short, you can go for mumbo-jumbo or you can go with scientific knowledge. Sadly, over half of mankind chooses to go with mumbo-jumbo. And when the mumbo-jumbo terrorists get nukes, that mumbo-jumbo may well spell the end to all civilization.