There's an interesting article here where a blogger used information from the Global Peace Index 2009 and World Value Survey to make graphs showing the differences in religious activity between peaceful and non-peaceful countries.
It's interesting... I've been reading this book about religious history for the past few months, and all the way back to the Greeks and Romans people have been saying that whether or not religion is true, people should follow it because without it society will fall apart. The data sort of suggests the opposite, that secular countries are more peaceful.
I'm thinking about being a religion major next year! If that happens, you can look forward to lots more exciting random posts about religions statistics. YAY!