I recently found my way to an online magazine called io9, and they appear to be running an unusual flash fiction contest at the moment. A fortnight ago they posted two images as the prompt for an 800 word flashfic challenge. Five stories (apparently from around 200 submissions) have been chosen to go to a public vote; the winning story will then form the basis for the next round alongside two new images; then the process repeats, I don't know how many times. The artwork is obviously pro stuff, from an outfit called Framestore; I can't speak for the stories yet, but I'm about to read them and vote. And, assuming the final five don't turn out to be garbage (the theme is space opera, which can be a mixed bag) I'm probably going to take part too. Why not?