Here are a few websites that I like:

Cornell University

Cycling News

Exploding Dog

Fab Labs

Google Art Project

Google Maps Pedometer

Google Scholar

Granta Design Educational Resources

Key to Orders of Trilobites

Little Fish Bicycles

Massachusetts Institute of Technology

MIT Cycling

NACA/NASA Technical Reports (links to archive in the UK because http://ntrs.nasa.gov/ is disappointingly down, as I write this webpage!)

NPR's Wait, Wait, Don't Tell Me!

Organic Farming Research Foundation

Cornell Lab of Ornithology Birdcams Project (Formerly Project FeederWatch)

Project Gutenberg

Resource Revival

Richard Sachs

Serious Eats

Sheldon Brown's Bicycle Articles

Stanford Encyclopedia of Philosophy

This-to-That

Udall Foundation

VassarStats

Web Plot Digitizer

Whitney Tool Speed and Feed Calculator

xkcd