Geospatial Technology

Data.gov is the home of the U.S. Government's Open Data. You can search by type of data, department, or topic. Link and examples:

The US Geological Survey (USGS) is a great source of national data and even some global data. Link and examples:

Other sources:

You can extract census data from American FactFinder (AFF) in Advanced Search.

1. In the Topics tab, choose the 2010 Census under Dataset. 
2. Click People to expand the option for Basic Count/Estimate, then click on a topic to add it to your selection box.
3. In the Geographies tab, query your geographies. 
4. For block level data, choose “all geographic types” in the Geographies tab. The Name tab might be quicker to use to get all of the blocks at once - use the Geographic Filter Options to query by state.
5. Close out of the Geographies tab and find the table you want. Click on it to reveal an option at the top to download.
6. Choose the csv - it has the FIPS code so you can table join it to a shapefile.

Discussion of these issues:

Data Sources:

Zip Code to ZCTA Crosswalk