Paul Spector’s website has a lot of useful information, including a page with his scales, and a page with his blog posts (some describe research I was part of), which make science more accessible.

Kristopher Preacher has many statistical calculators on his website.

Jeremy Dawson has excel tools for plotting interactions.

David Wilson’s Meta-Analysis Effect Size Calculator/Converter.

Fun Stuff:

This Stats Blog often has some nice visual representation of statistical ideas.