Article about Philadelphia Real Estate Gentrification
From my keywords I get the feeling a lot of people are trying to figure out which Philly neighborhoods are "HOT". This article does a good job explaining those areas and the neighborhoods where house prices and rents are appreciating. Sounds like there are really some people not only driving for dollars but pounding the pavement.
http://www.philly.com/philly/news/Gentrification_in_Philadelphia.html