Google maps mashup includes data on population, housing cost, housing market, schools, safety, health, climate, income/work, and age ethnicity for the continental US.

annoyingly, their "explains" don't say where the data comes from, so it's hard to know how up to date it is. However, it's neat.

Free Registration Required.

Information is at the sub-county level, but only one level beneath county, generally, so Philadelphia is broken only into Planning districts.

Funded by a 3-year grant from the William Penn Foundation, the Metropolitan Philadelphia Indicators Project combines two types of information to illuminate conditions and trends in our 9-county region (defined as the central cities of Philadelphia and Camden along with the Pennsylvania counties of Bucks, Chester, Delaware and Montgomery, and the New Jersey counties of Burlington, Camden, Gloucester and Salem). The first is a set of social, environmental and economic indicators that portray the quality of life in the region’s communities. The second type of information comes from an annual household survey conducted by Temple’s Institute for Survey Research, asking respondents across the region how they assess the quality of life in their communities. Tracking over time the changes in the indicators and in the survey responses, we can better understand how citizens’ perceptions relate to the changing conditions on the ground.