Map of McDonalds restaurants – image used under a creative commons license © Copyright Sasi Group (University of Sheffield) and Mark Newman (University of Michigan).
Maybe you have seen this kind of map before? Worldmapper has lots of this maps where the area of each country is modified according to the datas being mapped. I think it is a nice way to present data, as it gives an immediate idea of how those datas distribute worldwide. For instance, in the map above it’s immediately visible that McDonalds restaurants are very common in USA, Europe and Japan.