Reference

• Google
• Yahoo

• Four11 White Pages

• Canoe (Canadian Online Explorer)
• Sympatico.ca (comparable to Yahoo)

• The Internet Movie Database

• Google Maps
  
• MapQuest
  
• MapBlast

• Weather Channel, The

Geography

• CIA World Factbook

• digg
• del.icio.us
  

• Slashdot   [developers]
  
• Linux Today   [developer] [infrastructure]
  
• The Register   [Reg Developer] [data] [code]

• PHPBuilder.com - PHP articles

Software downloads

• Tucows

Computer hardware

• Tom's Hardware Guide

• Project Gutenberg (public domain)

• The Library of Congress
• The Internet Public Library

• WebMuseum

• Dict.org
• Wiktionary
  

• Online Rhyming Dictionary

• Merriam-Webster Thesaurus
• Roget's Thesaurus

• Wikipedia (open-source)

• U.S. Naval Observatory

• Flags of All Countries