Imperial War Museum
- Tells the stories of how the wars of the twentieth century have affected people, covering all aspects of life in wartime. Includes online exhibitions.
- http://www.iwm.org.uk/

The Roaring Twenties
- A look at how inventions shaped the culture of the early 1900s. Includes information on radio, appliances, the automobile, and the movies.
- http://www.classzone.com/net_explorations/U7/U7_main.cfm

Mass Entertainment
- Offers a glimpse into the turn-of-the-century entertainment world. Features highlights from the 1903 World Series, the St. Louis World's Fair, Coney Island, and the circus.
- http://www.classzone.com/net_explorations/U6/U6_main.cfm

1900 vs. Now
- A fun look at how the world changed from 1900-1998. From TIME Magazine.
- http://www.time.com/time/time100/timewarp/timewarp.html

Historical Atlas of the 20th Century
- Includes socio-economic trends, population and war statistics, and listings of world leaders.
- http://users.erols.com/mwhite28/20centry.htm

People's Century
- History of the people, for the people, as told by the people who lived it. From PBS.
- http://www.pbs.org/wgbh/peoplescentury/

Rpfuller.com: GCSE History Notes
- GCSE revision notes, covering Germany, the Treaty of Versailles, interwar diplomacy, the causes of World War II, Russia, and the Cold War.
- http://www.rpfuller.com/gcse/history/

Greatest Engineering Achievements of the 20th Century
- Describes the twenty greatest engineering achievements as determined by the National Academy of Engineering.
- http://www.greatachievements.org/