Best of History Web Sites (from EdTechTeacher,) is a resource of annotated and rated-by-content links to over 1200 history web sites across a broad range of related topics. The site also offers links of special interest to educators: hundreds of K-12 lesson plans, teacher guides, activities, games and quizzes and more.
MindPapers - David Chalmers organizes, streamlines and expands his collection of papers related to mind and neuroscience.
Motion Mountain - "The project aims to produce a simple, vivid and up-to-date introduction to modern physics, with emphasis on the fundamental ideas of motion. 'Simple' means that concepts are stressed more than formalism; 'vivid' means that the reader is continuously challenged; 'up-to-date' means that modern research and ideas about unification are included."