The Downtown Homeless Map tracks the number of homeless people in downtown Los Angeles; yesterday it received a revamp:

Today we’ve put online a new version of the maps, using a radically different methodology for showing the data. Instead of the dots of the old maps, this version takes the data and turns it into a “heat map” that shows the density of the population in different areas. … I think the main thing this new style brings is a more instant understanding of what’s going on. The dots made an interesting picture, and one that did work to tell the story, but in the end they generated a lot of questions.

The blogdowntown entry also has a bit on the methodology. Via Boing Boing.