I spent three days around Philly with my five year old daughter, while my wife had a business conference in the city. We had a great time, seeing historic sites, museums and interesting neighborhoods. I didn't notice anyone ruder than usual, nor did we have any trouble with crime. Maybe being from New York, I'm made of tougher stuff than many of the complainers on this forum. Anyway, the giant heart at the Franklin Institute was a huge hit with kids, plus the wonderful playground in Fairmont Park. The Mutter Museum was fascinating in its own disgusting way, while the Art Museum is spectacular. Try some scrapple at the Market and have a cheese steak in South Philly. If you go with a good attitude, you'll have a great time.