I am a big fan of mass transit. I think it makes cities more livable, and it has much to offer us in a world where driving an automobile has become an expensive proposition. So I was happy to see this video on Philebrity today of streetcars clanking around Philadelphia circa 1951. I had no idea that street-level trolleys used to be so numerous here - in the video they are seen gliding down Spruce Street in front of HUP and South Street between the Penn Museum and Franklin Field. Pretty cool stuff.