From the US Census Bureau.
From the website:
Latest TIGER/Line® Shapefile Release
- TIGER/Line®Shapefiles are spatial extracts from the Census Bureau’s MAF/TIGER database, containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas.
- They are made available to the public for no charge and are typically used to provide the digital map base for a Geographic Information System or for mapping software.
- They are designed for use with geographic information system (GIS) software. The TIGER/Line®Shapefiles do not include demographic data, but they contain geographic entity codes that can be linked to the Census Bureau’s demographic data, available on American FactFinder
2010 TIGER/Line® Shapefiles Main Page — Released on a rolling basis beginning November 30, 2010.
- Census Bureau Maps — Census 2000 Map Series, Online Mapping, and Census 2000 Centers of Population
- Cartographic Boundary Files — Generalized boundary files in (.shp), (.e00) and (ASCII) formats.
- Census 2000 Block Relationship Files — 1990 to 2000 Census Blocks.
- Census 2000 Census Tract Relationship Files — 1990 to 2000 Census Tracts.
- LandView® — A Federal Geographic Data Viewer
Great source of geographic and other data.
Can use it for mashups or, you can push beyond mashups to creating topic maps.
For example, plotting all the crime in an area is a mashup.
Interesting I suppose for real estate agents pushing housing in better neighborhoods.
Having the crime reported in an area and the location of crimes committed by the same person (based on arrest reports) and known associates of that person, that is starting to sound like a topic map. Then add in real time observations and conversations of officers working the area.
Enhancing traditional law enforcement, the most effective way to prevent terrorism.