About.com: Free outline maps of world continents and countries

Earth and Moon Viewer
A great resource for clickable satellite maps of the Earth and the Moon. Select views of Earth from the Moon or from the Sun, locate specific craters on the Moon by name, zoom in and out, and select different types of displays including topographic maps, weather maps and cloud maps.

Europe Map Archive
A historical and cultural atlas resource, providing maps of Europe in subjects such as natural resources and trade, the Ancient Near East, Classical Greece, the Hellenistic World and Roman Republic, Principate and Empire, and Late Antiquity and Early Medieval.

Geographic.org
Select from maps of countries or of continents, including population and contour maps, and many colouring maps

Google Map

Historical Atlas of the Twentieth Century
Provides a variety of maps which chart socio-economic trends, systems of government, cities, and wars throughout the 20th Century. Many of the maps are interactive and extremely detailed.

Make your own map

University of Texas Library
Collection of outline maps

World Map (image)