Reference

Map Quest  *favorite*
Offers maps of almost any location, as well as specific driving directions for single destinations or multi-point trips.
http://www.mapquest.com   (review rate bookmark)

Acronym Finder
Find the defintions of common Acronyms. Over 320,000 acronyms and counting.
http://www.acronymfinder.com/   (review rate bookmark)

Dictionary.com
Free online English dictionary, thesaurus and reference guide.
http://www.dictionary.com   (review rate bookmark)

Encyclopaedia Britannica
Searchable online version of the Enyclopedia Britannica. Includes other reference materials such as dictionary, thesaurus, and an almanac.
http://www.britannica.com/   (review rate bookmark)

How Stuff Works
Detailed, simple explanations of "How Stuff Works". Topics ranging from computers to travel.
http://www.howstuffworks.com   (review rate bookmark)

Internet Public Library
Resource index of online reference works. Includes almanacs, dictionarys, quotes, newspapers, etc. Live assistance from research librarians available.
http://www.ipl.org   (review rate bookmark)

Lexical FreeNet
Tool that allows you to search for rhymes and relationships between words and concepts.
http://www.lexfn.com/   (review rate bookmark)

Library of Congress
Official site of the Library of Congress, offering a wide range of information. Basic and advanced catalog search including books, periodicals, photographs, images, and sound recordings. Sections for librarians, archivists and researchers.
http://www.loc..gov   (review rate bookmark)

Questia
Online library containing over 70,000 online books and journal articles.
http://www.questia.com   (review rate bookmark)

SmartPages Yellow Pages
Searchable yellow page listings and business phone number index.
http://www.smartpages.com/   (review rate bookmark)

WorldCat [OCLC]
Online "card catalog" searching 1.3 billion items in 18,000 libraries world wide. Search for items in libraries near you, or worldwide.
http://www.worldcat.org/   (review rate bookmark)