Please visit Brenda Drake's blog for the list of participants.
I began with designing a cover for a book (or story) that didn't have a cover, and that proved more difficult. I then switched to redesigning a cover for Ender's Game, suggested by a friend. I haven't read Ender's Game since high school, but that doesn't mean I don't forget how epic it is. While the original cover(s) show space battles and Ender Wiggen, I went with a more digital-in-appearance route.
Links (made tiny for convenience):
Best of luck to all participants.