• DOI-10 Imagery
• DTED® 0 Terrain Data
• VMap 0 Vector Map
• VMap 1 Vector Map
• ONC Raster Map
• TPC Raster Map

The Federation of Earth Science Information Partners
The Federation maintains over 2,000 Earth Science datasets.
Every one is available to scientists, educators, policy makers, students, and the general public.
The vast majority of the data is free.
Federation partners are working together to develop new datasets that apply to specific interests bringing Earth science data to an ever expanding arena of users.

Geogratis
GeoGratis is a website and FTP site that distributes geospatial data of Canada.
Data is available for download, without charge!

Geoscience Australia
National Mapping Division (formerly AUSLIG)
These data sets are available for download. Before you download the data you will be asked for some details, which are used for licensing and monitoring product usage.

GIS Data Depot
Nationwide data sets include:

The Global Land One-km Base Elevation (GLOBE) Project
The GLOBE project has developed a 1-km gridded, quality-controlled global Digital Elevation Model (DEM).
GLOBE is an internationally designed, developed, and independently peer-reviewed global digital elevation model (DEM), at a latitude-longitude grid spacing of 30 arc-seconds.
The ongoing project makes use of several data sources to attain high data quality.
Important parts were taken from GTOPO30, but there are also additional contributions not part of GTOPO30.

National Geospatial Data Clearinghouse
The Geospatial Data Clearinghouse is a collection of over 250 spatial data servers, that have digital geographic data primarily for use in Geographic Information Systems (GIS), image processing systems, and other modeling software data collections can be searched through a single interface based on their descriptions, or "metadata".

Princeton Digital Map and Geospatial Information Center Internet Geospatial Resources

UNEP
United Nations Environment Program
Division of Early Warning Assessment (DEWA)
GRID Geneva
Global Resource Information Database
GRID's archives contain numerous high quality data sets at various scales (global, continental, national and subnational) on a variety of environment related themes.
The data are provided free of charge to users around the world, and can be downloaded online.

USGS EROS Data Center

GTOPO30 and HYDRO1K
GTOPO30 is a global digital elevation model (DEM) with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer).
HYDRO1k is a geographic database developed to provide comprehensive and consistent global coverage of topographically derived data sets, including streams, drainage basins and ancillary layers derived from the USGS' 30 arc-second digital elevation model of the world (GTOPO30).

World Data Center System

World Energy Resources