I've grouped these links by the identity of the sponsor. Within categories, the links are in no particular order.

National or international science organizations

• EurekAlert (sponsor: the American Association for the Advancement of Science)

http://www.eurekalert.org
• InScight (sponsors: Science Magazine & Academic Press)

http://www.apnet.com/inscight/
• Science Now Daily News (sponsor: Science Magazine)

http://sciencenow.sciencemag.org/
• NOVA - Science in the News (sponsor: Australian Academy of Science)

http://www.science.org.au/nova/

• Scientific American

http://www.sciam.com/
• Discover magazine

http://www.enews.com/magazines/discover/
• Popular Science

http://www.popsci.com
• Science News

http://www.sciencenews.org
• New Scientist Planet Science

http://www.newscientist.com/

• ABCNEWS.com Science and Technology

http://www.abcnews.com/sections/scitech/
• CNN Science and Technology

http://www.cnn.com/TECH/
• Fox News Science and Technology

http://www.foxnews.com/scitech/
• Los Angeles Times Science News

http://www.latimes.com/HOME/NEWS/SCIENCE/
• KR ScienceBase (a search engine from Knight Ridder news)

http://krscience.dialog.com/

• Helios Daily Science News

http://www.helios.org
• Science and Engineering Network News

http://www.senn.com
• SciNews (a search engine)

http://www.newswise.com/menu-sm.htm

• New York Times (free registration required)

http://nytimes.com/
• Washington Post

http://www.washingtonpost.com/
• Chicago Tibune

http://www.chicago.tribune.com/
• San Jose Mercury News

http://www.sjmercury.com
• Reuters

http://www.reuters.com

• The Internet Public library

This site has hundreds (thousands?) of links to magazines, newspapers, online texts, and more!
http://www.ipl.org