Library of Congress
Loc: Earth as Art: A Landsat Perspective
A really cool site showing Satellite (Landsat 7) images of unique geographical and meteorological phenomena. Images show cloud formations to rainforest devastation.
NASA
Nasa: Jsc Digital Image Collection: Earth From Space
Hundreds of amazing images of Earth from space. This site provides images of geographic regions, landscapes, cities, habitats, distinctive features, and much more. These images are easy to access and are of amazing quality.