I didn’t want to hijack this thread by cochrane:
http://boards.straightdope.com/sdmb/showthread.php?t=895309
Major Tom is amazing!!!
But I just ran across this guy on YouTube, who turned 100 in March. I’d never heard of him myself, but he is a prominent figure, and the last of the prosecutors of the Nuremberg trials.
Ben Ferencz, the last living Nuremberg prosecutor, turns 100 - YouTube Nuremberg prosecutor
Mr. Ferencz also has a Wikipedia article, and a lot about him all around the internet.
Feel free to add your stories of amazing centenarians.