This is a very awesome heatmap made by Strava, which displays very detailed data on where people bike and run worldwide. It also seems to be slightly biased towards people who can afford a smartphone.
An analysis of how race plays into college enrollment. The thesis is that race doesn’t really determine whether you go to college– it actually determines whether you graduate high school.
Another black and blue heatmap, showing where Uber users go. This is really the same demographic as the Strava users above, so now you can track where Yuppies go in every mode of transportation.
New York Times published this piece about income trends broken down by country and percentile. It has some cool interactive graphs.