Bill Beaty's The Science Hobbyist - Provides a large number of links to many topics of interest to the scientist, educator and science-curious. Main topics are amateur science, weird science, and cool science.
Donald Simanek's Pages - A comprehensive, quality collection of links as well as Dr. Simanek's own collected opinions. Topics include physics, history of science, pseudoscience, hoaxes, writing, education, skepticisism, humor, and quotes. The page is over 300K to load.
Homework Helpers - Links to useful sites for many different science disciplines, including physics.
Kathy - good links to physics sites suitable for secondary
Physics Linkpage - Links to pages and papers about physics, astronomy and related topics. Most of them are collected by the members of the Hawking-forum, a www-discussion-board. It often points directly to a paper instead of simply linking the homepage of the organization.