A streetcar travels down Market Street in 1906 -- less than a week before the Earthquake. Makes me dizzy with awe and something like fear.
More prosaic is the following, from the Amazon blog where I saw this, tipped off by Glenn Reynolds:
Quite apart from its subject matter, this sequence has particular historical significance as the first film made in 35mm format. It was originally thought to be from 1905. The correct date was recently determined by historian David Kiehn of the Niles Essanay Silent Film Museum, from clues such as old weather records and theater listings, the length and direction of shadows (from which you can determine the position of the sun in the sky, and the time of day), and the license plates on passing cars. Mr. Kiehn even ran the plate numbers and has the owner's name for all the cars.