I just completed a 2-day trip to Pittsburgh (took in a Nats game at glorious PNC park, my favorite ballpark in the world -- alas, the Nats lost).
Took great Maryland back roads to Gettysburg, then US 30 from Gettysburg to Pittsburgh -- a very nice mountanous road without much traffic at all. Made a stop at the very moving, spontaneous, Flight 93 Memorial in Shanksville (west of Bedford). This will become an official National Park, and will I'm sure be beautiful, quite soon, but catch this spontaneous display before they put up the official one.
Here are a few pix. The flag (where the plane hit the ground) is in the pastoral photo -- look hard.