National Geographic Sciencehttp://science.nationalgeographic.com/science/It is one of the largest nonprofit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, and the promotion of environmental and historical conservation.
PubChem
Nat Center for Biotechnology Info, Natl Library of Medicine, Natl Institutes of Health
http://pubchem.ncbi.nlm.nih.gov/PubChem is a search tool for chemical information, divided into three areas: Compounds, Substances, and BioAssays. Full entries provide detailed information with the most basic information—a general description, the molecular weight and formula, the structure, plus a Table of Contents (ToC) for the full entry—all easily found “above the fold.”
Medical journalshttp://www.freemedicaljournals.com/The Free Medical Journals Site was created to promote the free availability of full text medical journals on the Internet.
NASA Images
http://www.nasaimages.orgNASA Images, a free service of the Internet Archive and the U.S. National Aeronautics and Space Administration, provides "access to NASAs image, video, and audio collections." Divided into 5 sections: Universe, Solar System, Earth, Aeronautics, and Astronauts. Users may browse or search for media.
CogprintsUniv of South Hampton
http://cogprints.org/An electronic archive for self-archive papers in any area of Psychology, Neuroscience, and Linguistics, and many areas of Computer Science, Philosophy, Biology, Medicine, Anthropology as well as any other portions of the physical, social and mathematical sciences that are pertinent to the study of cognition.
Science.govhttp://www.science.gov/index.htmlScience.gov is a gateway to U.S. government science information and research results. Science.gov provides a search of over 55 scientific databases and 200 million pages of science information with just one query, and is a gateway to over 2100 scientific Websites.
Shodor.org(U.S. site)
http://www.shodor.orgThe Shodor Foundation, a nonprofit education and research corporation, is “dedicated to the advancement of science and math education, specifically through the use of modeling and simulation technologies.” Offers access to a repertoire of software and provides value-added aids, such as curriculum materials for students, sorted by grade and subject, for students, teachers, and parents.
Scirus Science Databasehttp://www.scirus.com/srsapp/Driven by the latest search engine technology, Scirus searches over 545 million science-specific Web pages, enabling you to quickly pinpoint scientific, scholarly, technical & medical data on the Web. Find the latest reports, peer-reviewed articles, patents pre prints& journals that other search engine miss.