"Scientific American" has been publishing since 1845, and at its Web site interested readers can find two full text articles from the current issue, as well as several features including selected short articles, news and analysis, short selections from 50, 100, and 150 years ago, an interactive "ask the experts" where scientific experts answer selected email questions, and weekly explorations and exhibits of scientific concepts. There are also interviews and a marketplace where SA merchandise is for sale. An archive of selected articles is available back to March 1996, and abstracts of articles from the January and February issues are also available. The site is searchable.
http://www.sciam.com/