Hey, I just got an account here, but I'm the person that saw them in Pittsburgh. I have another photo and a short video as well. To the person wondering if it was a map they were looking at - yes, it was. I saw it. Chris Nolan was pointing at intersections on the map and Wally Pfister (I think was the guy on his immediate left) was snapping photos of the map where he was pointing. They also seemed to be checking out the parking lot immediately across the street from them (they were standing directly in front of the Smithfield church). They were very focused on their work.
It totally made my day, hell, my year!