AllRefer.com - Reference and Encyclopedia
Browse encyclopedia articles in all areas of topics within earth & environment, history, literature & arts, health & medicine, people, philosophy & religion, places, plants & animals, science & technology, social science & law, and sports & everyday life. Source is the Columbia Electronic Encyclopedia.

Britannica
Now includes the entire Encyclopaedia Britannica, all 32 volumes, but no longer free. You can sign up for 72 hours of free access, but then have to cancel or you'll be subscribed. Also more than 70 newspapers and a directory of Web links, evaluated by Britannica editors.

Encarta Online
Encarta Concise Encyclopedia: not complete, but free!

Encyberpedia
Not every encyclopedia has a listing for Beanie Babies. This site does have a lot of links to information, well organized, though tarted up with ads.

Encyclopedia Smithsonian
Facts from the Smithsonian Institution.

Encyclopedia.com
More than 17,000 short articles from the Concise Columbia Electronic Encylopedia.

Information Please Almanac
An online dictionary, almanac and encycolpedia. Includes today in history.

Internet Encyclopedia of Philosophy
Another, including a nice timeline of Western philosophy.

Stanford Encyclopedia of Philosophy
Helps you separate Friedrich Nietzsche from Ray Nitschke.

Wikipedia
A well-known online Encyclopedia.

World Book Online
Free 30-day trial for the online encyclopedia. Then $50 a year.