http://ocw.mit.edu/OcwWeb/web/courses/cou
rses/index.htm#PoliticalScience - The
Massachusetts Institute of Technology offers
free downloadable college-level courses in
political science.
http://users.erols.com/mwhite28/20centry.htm
- This site provides oodles of interactive maps
and graphs that chart socio-economic trends,
systems of government, cities, and wars and
massacres throughout the 20th Century.