A Time-Lapse Map of Every Nuclear Explosion Since 1945 - by Isao Hashimoto
This is really interesting - it starts off slow, but gets to be horrifying after a bit. Once it gets up to speed it moves right along, but stops in 1998 for some reason. Oh well. :)
Then it recaps for each nuclear nation, showing what they did, and repeats each one a few times to let you see all the explosions they triggered. And at the very end you see what part of the Earth has been affected as a white overlay - it's pretty scary, especially if you live in the western US.
