Fantastic time lapse map of Europe, 1000 - 2005 A.D. MAY 15 2012
This time lapse covers more than 1000 years and shows the shifting national borders of Europe.
Update: The originals got taken down but the company responsible for the historical mapping software put up similar versions that I've embedded/linked above. But the new versions are worse and not quite so fantastic. Why is that always the case? (thx, andrew)