Math-Specific Tools

Math blogs:

Darren Kuropatwa from Winnepeg, CA (pre-calc and calculus)

Math on the EdHub page

Mathbits

NCTM's Illuminations

Math Forum

National Library of Virtual Manipulatives

MathsNet - Geometry

MathsNet - A-levels for Great Britain; takes some exploring to find US equivalencies, but interactives are great

Manipula Math Applets

Java Applets for Math (author is German)

Shodor Math Applets

Directory of even more applets!

Explore Learning Gizmos

Interactive Math

K12Math

Awesome Math Library

King's Online Math Activities (Algebra levels)

Ms. Saxman - Calculus Websites

Proof activities and lessons