A pet project using python, pandas/numpy/scipy, google maps and NASA's global population density grid data to guess a person's location bases on their distance from a known location.
The project's blog post: https://medium.com/@edden.gerber/guessing-someones-location-on-earth-based-on-their-distance-2d91b122f1ef
Get the data from here: https://sedac.ciesin.columbia.edu/data/set/gpw-v4-population-density-rev11/data-download