Eric Fischer has updated the Geotagger's World Atlas (previously covered on TGR here) by overlaying an analysis of photographers on the geo-located picutures. The result is even more stunning, capturing the different behaviors of locals (blue) and tourists (red):
He drew conclusions by examining other photos by the same photographer. If they had taken photos in the same city more than a month apart, then they were probably a resident of that city; otherwise, they were most likely a tourist.
This is a great example of intelligent data science, putting a second-order correlation on full display. The original dataset would not have yielded this insight. It took a transformation and recombination of the data before the inference could be drawn. I hope the count-the-words-in-the-tweets crowd is paying attention. Brilliant work.