my personal fav - nichols main floor.
love doorless restrooms that criss-cross. very elite.
I'll be honest and admit that Fatty should prob be the one writing this book. 
It's been too long since I've been on campus and I basically don't remember any of my old b-room hangouts. Almost scared to go now.
Everyone will be like "Who's the old pedophile looking d00d walking around campus w/ a camera taking pictures of bathrooms? Should we call the cops or tell our house mom or a GTA or something?" 
I've been walking around campus taking video on and off since I got back to Kansas, hoping to use it for a few Catmatt videos, so I think the campus is used to old pedophile-looking dudes with cameras.
That said, one bathroom that brings me fond memories is the one in the basement of Nichols Hall with the English GTAs ahd to keep their offices there. You had to pass through the men's room to get to the theater dressing rooms, and one night I was in my office late grading papers, decided to go down and take a dump, and while I'm sittin ghtere reading a copy of A Moveable Feast and savoring the expulsion of my feces, three girls come into the john en route to the dressing room.
Very uncool.
Oh, and you might want to include the bathroom in the Union that was rumored to be have a stall where gay boys made hook-ups. I didn't know which bathroom it was, so I just avoided taking a crap in the Union.