Eric Weisstein's Treasure Trove of Physics - Online encyclopedia of physics terms and formulas. Full searchable, and also browsable alphabetically and by topic. Part of Eric's Treasure Troves of Science.
The Net Advance of Physics - MIT resource providing discussions at various levels of sophistication that cover all areas of physics.
Physics 2000 - Provides an interactive opportunity to learn visually and conceptually about 20th Century science and high-tech devices.
Physics Central - A page on modern physics, such as quantum mechanics and black holes, and some mathematics.
Physics News Graphics - Diagrams (with captions) appearing in various AIP publications, sorted by category or by date.
Physics on MathPages - Articles, leaning towards a mathematical description, on a wide range of topics in physics.
Physics Post - A tutorial and article driven community. Votes, science news and a discussion forum.
Physics Today - The flagship publication of the American Institute of Physics (AIP). Provides feature articles, news stories, analyses, book and product reviews, a searchable job database, and obituaries.
Physics.org - Searchable database of physics resources from the Institute of Physics which matches a person's question, age and knowledge profile to handpicked sites. Also includes the Physics Life animation.
PhysLINK - Links to physics departments, physical societies, journals, job information, and other physics related information.
Physnet: The Physics Departments and Documents Network - Serves information from physics departments and institutes worldwide: departmental information, locally stored documents, authoring tools, free access journals, jobs, conferences and education material.
TheTangentBundle Physics Project - An experimental wiki-based collection of user-contributed articles on graduate level physics topics including subjects such as string theory, quantum field theory, mathematical physics and quantum mechanics.
What You Want To Know About Physics - Summarizes in simple language, without advanced mathematics, the foundations of physics. The index gives direct access to selected topics.
World Year of Physics 2005 - International effort to celebrate the 100th anniversary of the Miraculous Year (1905) and raise public awareness of physics.