Geometry Sites
The Geometry Center Welcome Page David E. Joyce (Wallpaper Groups/Tessellations)
The Math Forum at Swarthmore  Geometer's Sketchpad @ Key Curriculum Press 
IAS/Park City Mathematics Institute  GANG: Center for Geometry, Analysis, Numerics and Graphics  

History of Mathematics Site: Mac Tutor History of Mathematics Archive at St. Andrews
University in St. Andrews, Scotland

Some Journal Sites
Glasgow Mathematical Journal Home Page  E-math archive Electronic Journals
Springer Lecture Notes in Mathematics: Author & Editor List Zentralblatt  Zentralblatt review submission form
Mathematical Reviews subject classifications NISS information gateway  Electronic Information Resources in Mathematics
Mathematical Institutes
Centre Recerca Mathematica (Barcelona) Institute for Advanced Study (Princeton)
Isaac Newton Institute (Cambridge) Max-Planck-Institute for Mathematics (Bonn)
International Centre for Mathematical Sciences (Edinburgh) Mathematics Research Institute (FIM) of the ETH Zurich
Miscellaneous Math Sites
ATLAS of Finite Group Representations CTI Home Page
CTI Centre for Mathematics and Statistics Polytope Visualiza
Yahoo! Science:Mathematics