Mapping World Domination..er...Evangelism

I really like looking at maps - I think it satifies an urge we all have to conquer this vast thing called the earth by boiling it down to pretty pictures. Call it a world domination impulse, looking at maps gives us a satisfying comforting feeling that really it's all pretty simple. But ThinkChristian.net's Andy Rau posted a quick snippet about mapping global faith a few weeks ago that made me question this desire we have. He gave some links to a couple of maps he liked that attempt to diagram the geographic range of different faiths. This one at the German magazine Der Spiegel is mostly helpful if you kind of squint at it. The uniform color choices for whole regions imply that the population there are 100% of that faith. (It's unfair to Christians in Sri Lanka for instance to color the whole island Buddhist.) By contrast the global maps of evangelical Christianity at worldmap.org at least makes a clearer demarcation of uninhabitated areas but the color shading they chose (against a black background) makes it harder to process the information and the scaling of the four maps. At least both of these are NOT Mercator projections - you know, the kind that stretch the spherical surface of the earth to a rectangle that makes Greenland bigger than Africa. But why is there such a deficit in mapping faith well? The folks at gapminder do a brilliant job using U.N. development indicators to plot out global trends in literacy, poverty, HIV/AIDS etc. There's brilliant, highly-detailed and reliable data by folks like Todd Johnson over at the World Christian Database. So why hasn't anyone mapped the abundant faith data that exists in a compelling way against other indicators? Would it reveal disturbing trends, like the fact that Nigeria's Muslim half has much lower AIDS prevalence than its Christian half? What do you think?