I was talking with a friend of mine about the universe, and space. He started in on a size-comparison of us to the universe, and then extended it between us and our white blood cells. He pointed out that as far as cells go, white blood cells are pretty sophisticated, but in general they're pretty stupid (they attack good cells, for instance).
He posed the question, "What if we're just the white blood cells of some other being?"
We weren't talking about a god in the sense of the one people believe created the universe just for us, and knows what we're all up to and all that. We were talking about a god in the sense that we're gods to our white blood cells. They know nothing of the world outside our bodies, much like we know very little about anything outside of the universe.
It's an interesting thought.