The Stanford Math Circle Forum
 http://s10.invisionfree.com/StanfordMathCircle
Local math circles
 San Jose math circle
 Berkeley math circle
 San Francisco math circle
Local math activities
 Bay Area Math Adventures
 Bay Area Math Olympiad
Math resources on the web
 Frank Potter's math gems
 Interactive math miscellany and puzzles
 Mathematics sites for educators
 Fun math facts
 Mathematical software resources
 Problems of the week
 Art of problem solving
 Mathworld
 Math forum
 S.O.S. Math
 American mathematics competitions
 Factorization applet
 Arbitrary precision calculator
Let me know if you have suggestions for sites to add to the list.
