I head into the city once every week or so but most of the times I am on my road bike doing my Sunday loop.
I live about 9 miles outside the city and I have yet to pass another person on a fixed gear around here. I have seen one locked outside a bar in Glenside but that was in close proximity to Arcadia University so I am assuming it is a collage kid.
I had to meet my girlfriend downtown a few weeks ago and I must have passed ( I was on foot) at least 3 of those ugly alpha bikes and various other fixed gears it was a little weird how popular they are getting within the city. Out here in the burbs it is just me and a few others who enjoy the pain of a good climb and the feeling you get when you reach the top on a fixed .
I am down for a weekend fixed ride also