I read nakedphilly.com now and then an am really impressed by the small scale, but pretty voluminous, infill (literally) they have going on in Philly. Stuff like
this - small, 1-10 unit rowhouse construction on vacant parcels. If they just kicked it up a notch an reestablished the rowhouse streetscape throughout the historic rowhouse core (particularly north Philly), and dealt with some of the crime and segregation issues that plague the city, there would be no stopping Philly.
anyhow, this is top-notch housing built environment from a walkability/bikability standpoint