Philadelphia - is it safe to walk from the Market Station East Train to Penn's Landing?

I'd say it's safe. You're talking center city.. basically the Manhattan of Philadelphia. Now, when I say it's safe, I mean if you're taking the right precautions. Making this walk on a Tuesday afternoon at 1pm is going to be different than doing it at 3am on a Friday night. Just like with any city, there's good and there's bad. But if you're smart, pick a good time of day, and keep your eyes open, you'll be absolutely fine. There will be plenty of business people, hospital staff members, students, and other groups walking around. The walk is about 10 or so blocks, so it's not too too bad. Also, a cab ride would cost you about 6 bucks. That's what I'd do, especially if it were night time, or the weather was bad.