The University of Maryland's Global Landcover Facility (GLCF) provides free on-line download access to NASA's orthorectified Landsat ETM, TM and MSS satellite imagery world archives, and a variety of products derived from MODIS and other sensors.
	NASA's Visible Earth provides a searchable directory to a wide variety of images, visualizations and animations of the earth.
	The USGS National Map Seamless Data Distribution System provides free on-line download access to the National Elevation Dataset (NED) DEM data, the National Landcover Dataset (NLCD), and the Shuttle Radar Topography Mission (SRTM) DEM data, and orthoimagery.
	Canada's GeoGratis provides free on-line download access to a variety of imagery and vector data, mostly of Canada and the northern US areas.
	WebGIS provides free on-line download access to world and USA DEM data, and LULC (landuse) and DLG (vector) data for the US.
	TerraColor.Net markets global coverage of Landsat 7 15-meter simulated true color satellite imagery mosaics at affordable prices.
	ERMapper.com is the Earth Resource Mapping company website with information about their earth image processing, ECW compression, and distribution software products.
	EarthEtc.com demonstrates the Image Web Server technology for serving very large raster images in ECW or JPEG2000 format at high speed over the Internet.
	Terrashader is a sophisticated set of plug-ins for Lightwave and Maya for creating and rendering realistic landscapes using actual satellite and aerial footage of extremely high resolutions and file sizes in ECW format.