Map Enthusiasts

A few years ago, I read Guns, Germs and Steel by Jared Diamond, which gives a deterministic explanation of why civilizations have progressed the way they have. Among the factors that Diamond cites as determining the fate of a societies is latitude(how far North or South a location is). Locations with equal latitude have equal length days and often similar climates, suitability for crops, etc...

This map, originally created by Beardsley Klamm, has been circulating around the internet and shows some surprising comparisons between where European and North American cities in terms of latitude(eg: Rome is North of Denver).