Maps of War
I was going to post a flash map I found from this site, then realized there were a few other cool ones as well.

http://www.mapsofwar.com/maps.html

Maps I particularly liked were:

History - of - Religion
How has the geography of religion evolved over the centuries?

Leadership - and -War
Which Presidents have led the United States into its deadliest wars?

Imperial - History
Who has controlled the Middle East over the course of history?