Physical Reference Data - Held at NIST Physics Laboratory. - http://physics.nist.gov/PhysRefData/
Physics FAQ (Where to Find It) - Links where to find the FAQ documents for physics. - http://www.faqs.org/faqs/physics-faq/where-to-find-it/
Physics Formulae - A collection of frequently used physics equations compiled into several downloadable formats. - http://www.xs4all.nl/~johanw/contents.html
The Laws List - An alphabetical glossary of the various laws and theorems in this science. - http://www.alcyone.com/max/physics/laws/
The NIST Reference on Constants, Units and Uncertainty - Values recommended for international use by the Committee on Data for Science and Technology, International Council of Science. Navigation is by text search. - http://physics.nist.gov/cuu/Constants/