Flash fiction prompts

To encourage my Sudden Prose students to write more flash fictions, so they have more to choose from when it comes time to select a portfolio, I've been trying to come up with more prompts with which to help them along. Here's the one we tried in class today: Choose two fairy tale characters and put them in conflict to create your own fairy tale flash fiction. Possible characters include a wicked stepmother, a saintly stepdaughter, a princess, a prince, a troll, a dragon, a talking animal, a trusty steed, a fairy, and an old lady.

I'd be glad to hear of other flash fiction prompts that you've found successful, as well as see any responses you come up with to this one!