Libre Map Project
The purpose of the Libre Map Project is to aggregate and make digital maps and related GIS data available for Free.
Data - search and download Maps and other GIS data
Documentation - information on Cartography and GIS related topics brought to you by Wikipedia.
Email us - maps AT libremap DOT org
24k scale USGS DRG's - detailed topographic maps for all 50 states.
SVG boundary border files for all US states (including state, county, and town boundaries)
TIGER/Line - All 2003 data is available.
GeoNames - All USGS place names are available for searching. The data can be used to find appropriate DRG's.