Some other useful links:

USGS page with maps on hurricane Mitch, accessible in English and Spanish.

Internet Guide to different aspects of Geographical Information Systems, why they are important, available resources and services, and updated news.

What is GIS-an introduction from the U.S. Geological Survey teaches you how GIS works and has been applied through history to the present day.

The Bureau of Transportation Statistic's Geographic Information Services are a national resource for transportation spatial data and GIS in transportation information

The Global Demography Project is an effort to generate consistent, spatially referenced global population data sets for global and regional environmental analysis, demographic research, etc. with links to sites with socioeconomic and demographic data sets.

"El Poder de la Información A Través de un Enfoque Geográfico" by Aeroterra, S.A. (Argentina), provides GIS and Remote Sensing products, services, training and support. Site includes reference documents, on-line demos, and links.

Introductory References About GIS

List of GIS related Organizations