http://www.usgs.gov
United States Geological Survey: links to the National Atlas of the United States (and interactive mapping application), map learning materials, GIS databases, and Geographic Names Information System

http://www.census.gov
U.S. Census Bureau: TIGER files, interactive mapping application and census data products

http://www.epa.gov
Environmental Protection Agency: EPA National GIS Program and interactive mapping application (Maps on Demand)

http://www.geo.ed.ac.uk/agidict/
International GIS Dictionary

http://www.esri.com
Environmental Systems Research Institute: producers of Arc/Info, ArcView, ArcExplorer, free software and data downloads and tutorials, on-line internet mapping applications

http://www.cast.uark.edu/local/hunt/
University of Arkansas, Center for Advanced Spatial Technologies: guide to on-line geospatial and attribute data

http://www.utexas.edu/depts/grg/
University of Texas: links to geography course materials, web sites of university GIS courses, map collections, on-line data sources

http://www.ncgia.ucsb.edu/
National Center for Geographic Information and Analysis, University of California, Santa Barbara: research projects, core curriculum for GIS education

http://www.gisdatadepot.com/
GIS Data Depot: an amazing source of free, downloadable GIS data, at many levels of geography.

Dr. Carol Hanchette's Favorite Links
NASA CHAART page, with vector-borne disease applications

Dr. Sam Soret -- Course-Related Links

Animated Maps of Tuberculosis in San Francisco (Stanford University)
http://cgi.umbc.edu/~chpdm/healthgeo/

Health Geographics Resources

EPA's Envirofacts Data Warehouse

"Just Another Medical Geography Page"

http://www.dartmouth.edu/~atlas/
The Dartmouth Atlas of Health Care in the United States

http://www.ncgia.ucsb.edu/
National Center for Geographic Information and Analysis

Dr. Gerard Rushton -- Course-Related Links

http://www.uiowa.edu/~geog/
University of Iowa Geography

SatScan Software for Calculating theSpatial, Temporal and Space-Time Scan Statistics