Not "a lot", no. You may have gotten that impression from me.

Touristy Things I've Done In Philly:

Independence Hall: Interesting tour, well worth it.
Liberty Bell: Stand on line for maybe an hour to walk past a bell with a crack in it and look at it for maybe two minutes.
Betsey Ross House: Total waste, IMO.
Art Museum; The "Rocky" Steps. The museum is very good, too.
Museum of Science & Natural History (Franklin Institute): Pretty good, not great.
Barnes Museum: Great, if you like French Impressionism (I don't). But you have to write away for tickets in advance (Find their website).
Philadelphia Zoo: Good, if you like zoos (I do), but you need a car to get there. Very expensive cab ride.
South Street: Where all the hippies meet. Funky clothing stores, head shops, sex toys, cafes, etc.