Global Mapper is more than just a viewer capable of displaying the most
popular raster, elevation and vector datasets. It converts, edits,
prints, tracks GPS and allows you to utilize GIS functionality on your
datasets in one low-cost and easy-to-use software package.
Global Mapper also includes the ability to directly access multiple
online sources of imagery, topographic maps, and gridded terrain data.
This includes access to worldwide high resolution color imagery from
DigitalGlobe (watermarked access for free) and access to the entire
TerraServer-USA database of USGS satellite imagery and topographic maps
free-of-charge. Global Mapper also has the ability to easily access WMS
data sources, including built-in access to elevation data and color
imagery for the entire world, and to view elevation data in true 3D with
any loaded raster imagery and vector data draped on top of it!