There is a fantastic essay over at Hunger Mountain-Corn Maze by Pam Houston-on the dividing line between fiction and creative nonfiction.
Within this essay is a very simple, to the point writing prompt. Read the essay first to see what context it is in, then see what you can do with the prompt:
"Write down all of the things out in the world that have arrested your attention lately, that have glimmered at you in some resonant way. Set them next to each other. See what happens."