An interactive map of Philadelphia homicides in 2007 from the Philadelphia Inquirer

An interactive map of murders in the city of Philadelphia in 2006 from the Philadelphia Inquirer.

This site is a non-profit, freely browsable database of crimes reported in Chicago.

It is not affiliated with the Chicago Police Department or with Google Maps. It is not an official source of crime information for the city of Chicago. Rather, it is an alternative view of public record that is available elsewhere.

Google maps mashup includes data on population, housing cost, housing market, schools, safety, health, climate, income/work, and age ethnicity for the continental US.

annoyingly, their "explains" don't say where the data comes from, so it's hard to know how up to date it is. However, it's neat.

The US Census provides thematic maps at various levels of geography and for many data points.

The map images as well as the satellite imagery belong to Google and are pulled from maps.google.com. The data is extracted from the 2000 United States Census and can be downloaded from www.census.gov.