From policymap.com, you can access all of the information you need about a place without having to visit multiple websites or task staff and consultants with collecting and analyzing data. Policymap.com houses thousands of indicators related to demographics, real estate markets, crime, schools, housing affordability, employment, energy and public investments. Much of this data is available to the public for free — other proprietary data, such as demographic and employment projections, and home sale trends — are only available to paying subscribers. All data comes with brief, reliable, easy-to-understand definitions. For a complete listing of data available in policymap.com, please refer to the Data Directory link in the upper right of the web page. TRF hopes that you will suggest other datasets you’d like to see incorporated into PolicyMap. Click on the Suggest a Dataset link at the bottom of the web page to send us your ideas.

The City of Philadelphia provides maps of City Services, service areas, and zoning rules.

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.

" Each year this project compiles a history of Mexican migration to the U.S. based on interviews conducted in Mexico during the winter. Topics include employment, earnings, and use of U.S. social services. The site features downloadable data, maps, and a list of publications. Also includes oral histories, and an online exhibit of religious folk art retablos (1900-1993). In English and Spanish. The MMP is a research effort between investigators in Mexico and the United States." (via LII)

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

Twentieth century conditions in maps.

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.

Geographic Information Systems (GIS) software relies on data sets that cover the whole planet. To cope with the flood of GIS data and their formats, programmers have created several open source libraries and GIS suites. This article gives a short introduction to the range and depth of GIS tools and libraries available for UNIX® and Linux®.

EDINA is actively seeking global and regional geographic datasets which can be made available to the UK Higher and Further Education community. Many global datasets are now being published via web map servers and are accessible through the use of interoperability standards. EDINA have created a Web Map Viewer, which will allow anyone with Internet access to view geographic data available through web map servers around the World.

Census page listing Hurricane Katrina related info.

List of data sets available from USUS. Huge and quite up to date.

List of data sets available from USUS. Huge and quite up to date.

he World Health Organization Collaborating Center for Remote Sensing and GIS for Public Health (WHOCC) at LSU is dedicated to the application and advancement of geographic information science (GISc) and geographic technologies for Public Health and disease modeling.

Federal Gateway to information about Katrina in New Orleans. Includes maps, GIS data, interactive mapping packages, etc.

Collection of data and maps from UCGIS related to Katrina and New Orleans