Nice writeup on Plastic, with a link to a good article about the Pittsburgh phenomenon of unlicensed cabs, the jitenys. I think that one of the major contributing causes of PGH's "youth flight" is the lack of straight bars open downtown, and the fact that you can't get anywhere easily without a car (The fact that they're going to cut back on bus service doesn't help, either). I've called for a Yellow Cab, waited 45 minutes, and had it not show up before. Jitneys fill a need, but it's still not enough.