English Server Philosophy E-Texts -- The EServer, founded in 1990, is now based at Iowa State University. It has many major philosophy texts online.
Internet Encyclopedia of Philosophy -- The Internet Encyclopedia of Philosophy was founded in 1995 for the purpose of providing detailed, scholarly information on key topics and philosophers in all areas of philosophy. It is housed at the University of Tennessee-Martin.
Stanford Encyclopedia of Philosophy -- The Stanford Encyclopedia of Philosophy is a dynamic reference work and is a publishing project of the Metaphysics Research Lab at the Center for the Study of Language and Information (CSLI) at Stanford University.
Noesis -- Noesis is a limited area search engine for open access, academic philosophy on the Internet.
Society for the Advancement of American Philosophy -- The Society for the Advencement of American Philosohy exists to advance American philosophy by promoting interest and research in its history, encouraging original and creative work in its spirit, and providing forums for the exchange of information and ideas.
PhilPapers -- PhilPapers is a comprehensive directory of online philosophy articles and books by academic philosophers. We monitor journals in many areas of philosophy, as well as archives and personal pages. We also accept articles directly from users, who can provide links or upload copies. Some features require that you sign in first, but creating an account is easy and free.
Entitled Opinions -- Entitled Opinions is a literary talk show on Stanford University Radio, KZSU, in which Professor Robert Harrison interviews guests about issues that range from literature and philosophy to politics and sports. The show's itunes page has a wonderful archive.