Links
Atomic physics
Links from Laurence Livermore National Lab - a huge list
Links from the Weizmann Institute - another large list classified by country
FOCUS - NSF Physics Frontiers Center
ITAMP
Center for Theoretical Atomic, Molecular, and Optical Physics

University of Windsor - Physics
Ultrafast links

Quantum computing
Lov K. Grover
Peter Shor 
Center for Quantum Computation
Physics 219 at Caltech by Preskill
Quantum Computing at Xerox
Quick Reviews in Quantum Computation and Information

Research tools
LANL e-Print archive
Numerical Recipes Home Page
Some useful computing links

Great teaching aids
Physics 2000
Homework Service 
What is Physics good for? archive
Quantum Mechanics Problems- Francis Robicheaux

Professional organizations
Canadian Association of Physicists
American Physical Society
American Chemical Society
Americal Association of Physics Teachers
Gordon Research Conferences Home Page
Association for Women in Science

General scientific information
APS Centennial Celebration
Eric Weisstein's World of Mathematics

Large Standard Model Chart

The Particle Adventure

NIST Chemical Formula Search

NIST Chemical Name Search

Periodic Table of Elements (YOGI'S Behemoth)

Other interesting webpages
Denise Kirschner's webpage

Odds and ends
Google
Websters
Foreign language dictionaries at Word Reference
Technical Writing
Encyclopedia of Western signs and ideograms at Symbols
Word Oddities and Trivia