I teacher friend and I were talking about books, and something prompted her to show me the book If the World Were a Village by David Smith. It is a relatively short picture book that puts our world into terms of a village of 100 people. It talks about the numbers of males/females, religions, ethnicities, etc.
The copy I viewed was a little older--newer editions have since been published. If I teach religion next school year, I will definately get this to add that perspective to my students' education.
Here is a cute YouTube video of this concept: If the World Were a Village .