Well right now I'm very fascinated with 1920s Berlin. I mean probably the more interesting thing would be to go to the beginning of civilization or precivilization - like polytheistic times. It would be interesting to see what came before modern religion and culture - what circumstances created the environment or the need for it.
We'd be working in our motel room through the night and I'd come up with an idea at two in the morning and he'd start jumping up and down pacing across the room or whatever.