I'm often surprised how relatively out-of-the-way and even quite obscure places have already been tagged on location services. All that information that is so rapidly accumulating, all those interesting uses for it, all that value, all that potential to reveal things that we didn't already know. And that's before we get to the stuff that accumulates less directly. The data that we leave behind us like vapour trails. Which is why I love stuff like this.
Photographer Eric Fischer started creating The Geotaggers' World Atlas, using the photo locations taken from the public Flickr and Picasa search APIs to illustrate and plot where people are taking pictures in cities around the world. The cities are then ranked based on the density of photographs taken around their centre, with New York coming out top.
Because some people interpreted them to be simply maps of tourism, he then attempted to find out if that was really true by mapping the origin of these pictures. Each city (like London, below) is plotted separating the pictures taken by locals (in blue, defined as people who have taken pictures in that city over a range of a month or more), from those taken by tourists (in red, defined as people who took pictures in that city for less than a month but seemed to be a local of a different city) and those of unspecified origin (in yellow).
The cities in the Locals and Tourists set were then ranked by the number of pictures taken by locals and this time, it was London that came out on top. As Eric says:
"Some cities (for example Las Vegas and Venice) do seem to be photographed almost entirely by tourists. Others seem to have many pictures taken in places that tourists don't visit."
For some reason, it makes me happy that Londoners take a lot of pictures of their own city.