University Library Digital Spatial Data Catalog - Searchable catalog of data/metadata managed by Numeric and Spatial Data Services at the University of Michigan Library - http://quod.lib.umich.edu/cgi/b/bib/bib-idx?g=gisall
Geospace - Provides spatial data services. - http://www.geospace.co.za/
NOS Data Explorer - Offers interactive mapping tools that allow users to locate NOS products in any area in the United States and its territories through a metadata catalog. - http://www.noaa.gov
USGS Geography - National mapping information from the U.S. Geological Survey. A good place to start the search for many kinds of GIS data. - http://geography.usgs.gov/
Kansas Geospatial Community - State of Kansas Data access and support center (DASC). DASC catalogues, archives, and distributes databases with FGDC compliant metadata and direct FTP access. - http://gisdasc.kgs.ku.edu
microDATA GIS - Spatial databases and enhanced 911 (E911) mapping and database solutions. - http://www.microdatagis.com
Forest Spatial Information Catalog - The Forest Spatial Information Catalog (FSIC) is a central repository for forest related spatial metadata. - http://gislab.cifor.cgiar.org/fsic
3D landscape visualization for MAXON CINAMA 4D - Offers wire-meshes for the rendering software MAXON CINEMA 4D taken from the GTOPO30 dataset of the U.S. Geogical Survey. Also provide matched satellite images textures from NASA. - http://www.digital-landscape.com/
@City Inc - iStreetView - 360-degree Geocoded Street level Imaging on the Web - http://www.atcity.com
Doyle's GIS Info Page - Information about GIS and Links to GIS site for mostly free data for the USA. - http://www.doylesdartden.com/gis/
GIS Express - Offers satellite and aerial images. - http://www.gisexpress.com
Go Spatial Limited - Producer of digital geographic data suitable for reference base mapping at global, regional or national levels. - http://www.gospatial.com
Geosign Corporation - Provides geographic data for franchises and yellow-pages listed companies. - http://www.geosign.com/
Community Mapping Network - Created to share a wealth of natural resource information and maps with communities in British Columbia, Canada. Allows users to add data. - http://shim.bc.ca/
Census Watch - ESRI sponsored clearing house, providing information about US census tract TIGER data availability and modifications. - http://www.censuswatch.com/
The Climate Source - Distributor of spatial climate data developed by Oregon State University's PRISM mapping program. - http://www.climatesource.com/
Community Cartography - An Internet mapping service and spatial data warehouse. - http://www.comcarto.com
New York State GIS Clearinghouse - Operated by the New York State Office for Technology. Provides access to the New York State GIS Metadata and Data Repository. - http://www.nysgis.state.ny.us/
Geographic Data Technology - Digital map database compiler focused on the Americas. - http://www.geographic.com/
Rhode Island GIS - Data clearinghouse for the state of Rhode Island. - http://www.edc.uri.edu/rigis/
Rainwater Basin GIS data site - This site provides free GIS data sets pertaining to the Rainwater Basin wetlands in Nebraska. - http://www.calmit.unl.edu/rwb
GeographX Digital Mapping - New Zealand land information and GIS services. Site offers some free data. - http://www.geographx.co.nz/
Louisiana Statewide GIS - Contains GIS and mapping data on the state of Louisiana. - http://atlas.lsu.edu/
Tennessee Spatial Data Server - GIS data for the state of Tennessee. DOQQs, DRGs, DEMs, boundaries, wetlands, and geology. - http://www.tngis.org
MapFocus GeoTIFFs - Digital raster graphics for GIS and CAD applications. Includes continental US coverage, full resolution topography. - http://www.mapfocus.com/
Hawaii Statewide GIS Program - Free downloadable GIS spatial data, metadata, and maps. - http://www.hawaii.gov/dbedt/gis/
Texas Natural Resources Information System - Clearinghouse for natural resources and GIS data. Online holdings include DOQs, DEMs and many vector datasets. - http://www.tnris.state.tx.us/
GIS Data Depot - Provides free GIS data downloads and creates custom spatial data CD-ROMs. - http://www.gisdatadepot.com/
Energisite.com - Internet delivery of online digital and raster well logs, well data, GeoCadd culture, and Analytical software using esri and AutoDesk MapGuide and AnGIS technologies. - http://www.energisite.com/
GTOPO30 - Global Topographic Data - Digital elevation model (DEM) developed to meet the needs of geospatial data users for 30-arc second elevation data. - http://edcwww.cr.usgs.gov/landdaac/gtopo30/gtopo30.html
Digital Chart of the World - Download the boundaries and layers of different countries, in Arc/INFO export format. - http://www.maproom.psu.edu/dcw/