How crazy & amazing is this! Among the world's most unique dialects is... the Philadelphia accent! It's certainly hard to imitate if you're not from here (that's why Tina Fey does such a great job), and maybe that contributes to way! According to a famous liguist from the University of Pennsylvania, the city is the "gold standard when it comes to language patterns because the pronunciations of words varies from generation to generation, and of course, neighborhood to neighborhood."
Most definitely true! You could go to one neighborhood and they could have a completely different variation of the Philly accent than another! It's nice to finally get some recognition for saying things like "downna shore" and "wooder"!