The most beautiful maps are somehow useless. You look at them not to decide where you’re going, but rather to see constellations that are rarely visible: details that, from the ground, never coalesce into a coherent picture. Eric Fischer has fashioned a set of maps that depict just such constellations. Using photographs from Flickr and Picasa, Fischer has placed a colored mark on a map where each picture was taken. As he explains:
Blue points on the map are pictures taken by locals (people who have taken pictures in this city dated over a range of a month or more).
Red points are pictures taken by tourists (people who seem to be a local of a different city and who took pictures in this city for less than a month).
Yellow points are pictures where it can't be determined whether or not the photographer was a tourist (because they haven't taken pictures anywhere for over a month). They are probably tourists but might just not post many pictures at all.
The results (above is Stockholm) trace where people go and what they photograph, arcs and blocks and spangles of presence.
(Thanks, The Map Room.)
Source: Eric Fischer