The Net Advance of Physics:

GENERAL PHYSICS OVERVIEWS

• Eric's Treasure Trove of Physics, by Eric Weisstein (Actually a dictionary of physics)

• Physics Unbound, edited by Mark Lindeman
  An attempt to compile a virtual textbook from materials on the Net. Unfortunately, it seems to have vanished as of 96/12.
• Fascinations of Physics, by Jacqueline D. Spears and Dean Zollman A 1986 freshman textbook (© Benjamin-Cummings Publishing Co.) being put in pdf format by the authors. Under construction.
• Galileo and Einstein, by Michael Fowler Homepage of an undergraduate physics course with historical emphasis. Extensive lecture notes online. (University of Virginia)