Geological Society of America
Organization's homepage, with information on officers, meetings, and publications.
This award-winning site contains current information on geology news, events, and hot topics. In addition, GeologyLink provides links to physical geology courses from around the world, virtual field trips, student and instructor forums, and an "ask the professor" section.
Online dictionary of GIS terms provided by the Association for Geographic Information and the University of Edinburgh Department of Geography. Site includes definitions to 980 terms, searchable by keyword or through a variety of lists, including alphabetical and categorical.
From the US Geological Service in collaboration with some twenty different federal agencies, includes data on health, the environment, demography, agriculture, climate and geology from 1990-2002.
United States Geological Survey
USGS homepage, with information about research activities, results, and products, and includes digitized books, maps, and other data.