GIS - Megasites

Google's GIS Resources

Infomine's GIS Resources

GIS Data Depot
This site allows you to browse for United States as well as worldwide GIS data. A majority of the data is available for downloading free of charge, and value-added or customized data can be purchased online. This site requires users to create a free account.

Alexandria Project
The goal of the Alexandria Project is "to build a distributed digital library (DL) for geographically-referenced materials." A major component of this project is the Alexandria Digital Library (ADL), providing access to geographic datasets.

Starting the Hunt
This is a guide to on-line and mostly free U.S. geospatial and attribute data. The page is well-organized, allowing the user to search international, national and state map data catalogs or to browse through a subject-oriented list.

Geography Network: Data
Download free data from the Geography Network. This site has a large collection of geographic data from around the world.

Geospatial One Stop

Global Land Cover Facility

The Harvard Geospatial Library

NGA Raster Room

United States Geological Survey

The National Map

Conservation Geoportal