I live about 20 minutes south of Gettysburg and take the trip up there quite often. I love the battlefields. If you go, be sure to hit up Devils Den, Round Top and the visitors center. It's pretty nice if you're into that kind of thing. I love history, so I tend to go a bit more than most. They've also got a nice little town up there with a bunch of museums.
Last time we went, we made a trip to the Gettysburg Museum of History which has quite a bit of old war artifacts, JFK stuff, and a ton of misc other cases. They go on donations, so that's nice. We also took a private tour of the Shriver House Museum, which was definitely pretty cool too.
It's a neat town with a ton of history, and they've got some outlets up there too that we visit at least once a month.
If you're going to be up there for a bit and like to meet up, shoot me an email baltimore at gmail.
Wouldn't mind visiting up there again before it gets too cold.