For our final project, my group was required to select a location, identify two groups there, and get them to interact in anyway we chose. We picked the deli inside the Journal Square PATH station. It turned out to be an amazingly difficult but rewarding project.
There are my condensed observations of the PATH station near where I live. Beware of the hard-ass Port Authority Police Department -- they do NOT like you taking photos of the station. It does help to say you're from the neighborhood, though.