Via Can Turtles Fly:
Oldest Photo of a Person
Boulevard du Temple by Daguerre, Paris, France (circa 1838)
(source: Scanned from The Photography Book, Phaidon Press, London, 1997. Downloaded from Wikipedia Commons on June 24, 2012)
Previously:
Nasty bugger what with the devil horns and all

Oldest known photograph of a tornado
Image ID: wea00206, NOAA's National Weather Service (NWS) Collection
Location: 22 miles southwest of Howard, South Dakota
Photo Date: 1884 August 28
From NOAAImage ID: wea00206, NOAA's National Weather Service (NWS) Collection
Location: 22 miles southwest of Howard, South Dakota
Photo Date: 1884 August 28
HT: Wicked Weather Pics
And:
Oldest Known Pornography Found in France