We've lived here for a year - more or less without incident. I work at broad and Walnut - and I take the subway any time I am running late or the weather is not good enough to walk. I have never once felt uncomfortable or threatened on the subway. I am definitely not "urban" either - I'm a 27 year old red head from Connecticut.

OP is going to Penn. So the subway ride is Broad Street Line, Spring Garden to City Hall, then trolley (any trolley EXCEPT 10) from City Hall to 37th St. Usually takes me about 25 mins. Trolleys come QUICK, never usually have to wait more than 4-7 mins, so the biggest time waste of the trip will be waiting for the BSL.

I've lived by 11th and Spring Garden for almost a year and also work by Broad and Walnut. In fact, I'm almsot identical - except I'm 28 and from Philly. No problems that I haven't had in Center City proper. I usually take the subway in the morning and walk home in the evenings if the weather nice. If it's late I take cabs if I'm by myself.

I also second previous posters about Jose's, its great. Also right on the corner of 10th and Spring Garden is Sazon, a really great BYO Venezuelan. A couple doors down from there (before 9th) is Siam Lotus which is a great Thai resturant.