(YouTube link)
Silent film footage taken in 1909 by Thomas Edison at Stormfield (CT) at Mark Twain's estate. Twain is shown walkng around his home and playing cards with his daughters Clara and Jean. The flickering is due to film deterioration, but this is the only known footage of the great author.
-via Grow-A-Brain
I wonder if anyone will ever take the clip and try to remaster it. Its so short a clip that you could almost go frame by frame in adobe and fix it.