Via kottke.com, here's a fun clip of Market Street in San Francisco from the front of a trolley car . . . circa 1905. I love how pedestrians, horse-drawn carriages, and cars pushed by people weave in and out; hey, when the fastest thing on the road is going maybe 8 mph, it's not really as necessary to look both ways before you cross.
Also, whenever I look at old pics or videos, I never fail to notice how wide the streets look. I don't know SF well enough to know if Market Street is just as wide now, but it probably doesn't look as wide, between two parked rows and much bigger vehicles.
Of course, a terrifying (or exhilarating?) thought comes to mind. Circa the 2100's, will footage of 2009 look similarly dawdling and disorganized? Speed and organization has meant vastly more efficiency but also more danger. Will we figure out how to manage our streets to squeeze even more efficiency without compromising safety? Keep an eye out; and keep on taking footage.