Maps 

• About: Geography / About: World Atlas and World Maps
  Maps and geographical information for countries, cities, and regions. Includes blank outline maps.
• American Memory: Map Collections
  Scanned copies of maps from the Library of Congress.
• Civil War Maps
  "Civil War Maps brings together materials from three premier collections: the Library of Congress Geography and Map Division, the Virginia Historical Society, and the Library of Virginia....all available for the first time in one place."
• David Rumsey Historical Map Collection
  This site "has over 8,800 maps online. The collection focuses on rare 18th and 19th century North and South America maps and other cartographic materials. Historic maps of the World, Europe, Asia and Africa are also represented."
• Driving Directions:
  -- Google Maps
  -- MapQuest
  -- Yahoo! Maps
• Earth: A Graphic Look at the State of the World
  Via maps and graphs, this site shows and compares information on such topics as global ecology, human conditions, energy supply, food production, pollution, warfare, and wealth.
• FlashEarth
  An interface to GoogleEarth and several other online maps using Flash to enable easy control of the map view.
• Google Earth
  "Google Earth combines satellite imagery, maps and the power of Google Search to put the world's geographic information at your fingertips." Basic package is free, but must be downloaded and installed. The Google Earth Community discusses plenty of cool tricks and add-ons for the basic program.
• Google Maps / TerraFly / NASA World Wind - Google Maps lets you either view a conventional map of an area, or switch to a zoom-able satellite view. TerraFly (works best in Internet Explorer) shows you an area from the viewpoint of a low-flying plane. World Wind (from NASA) lets you zoom from satellite height to any place on Earth. There are a number of World Wind add-ons available.
• Maplib.net
  "Maplib.net turns pictures into zoomable & panable views in easy steps and enables new ways of viewing pictures, just like Google Maps does." You can create your own custom maps, complete with tagging, annotation, markers, and more.
• Maps in Our Lives
  "Celebrating a thirty-year partnership between the Library of Congress and the American Congress on Surveying and Mapping (ACSM), the Maps in Our Lives exhibition explores surveying, cartography, geodesy, and geographic information systems--and draws on both the Library's historic map collections and the ACSM collection in the Library of Congress."
• Military Campaign Maps
  "Maps showing campaigns of major military conflicts including troop movements, defensive structures and groundworks, roads to and from sites of military engagements, campsites, and local buildings, topography and vegetation."
• MultiMap.com
  "Multimap.com is Europe's most popular mapping web site, offering a range of free, useful services to assist with everyday life. Key features include street-level maps of the United Kingdom, Europe, and the US; road maps of the world; door-to-door travel directions; aerial photographs; and local information."
• National Atlas of the United States
  From the U.S. Geological Survey, "the updated National Atlas is designed to provide a reliable summary of national-scale geographical information." Interactive design allows users to draw their own maps with the features they select.
• National Geographic: Maps and Geography
  All sorts of maps, both of the United States and the world.
• Neighboroo
  Maps showing climate, health, population, and other statistics about the U.S. and its neighborhoods.
• Perry-Castañeda Library Map Collection
  Tons of maps both current and historical.
• Periodical Historical Atlas of Europe
  Policical maps of Europe at one-hundred year intervals between 1 A.D. and 1700 A.D., plus maps of Rome and of Roman battles.
• strange maps
  A blog highlighting odd, strange, and sometimes beautiful maps for a wide variety of subjects.
• TopoZone
  USGS topographic maps of the United States in a searchable archive.
• The UC Atlas of Global Inequality
  "The Atlas of Global Inequality explores some aspects of inequality using online, downloadable maps and graphics. All these materials can be used freely providing they are attributed to the UC Atlas of Global Inequality."
• WorldAtlas.com
  Maps and facts about the places of the world. Includes current times, map clip art, distances, and more.
• WorldMapper
  "Worldmapper is a collection of world maps, where territories are re-sized on each map according to the subject of interest." Work in progress.
• World War II Military Situation Maps
  From the Library of Congress, "the World War II Military Situation Maps contains maps showing troop positions beginning on June 6, 1944 to July 26, 1945."