My favorite short short story is by Hemmingway. It is all of six words long – but boy, does it pack a punch.
It goes, “For sale, baby shoes, never used.” Wow!
It turns out that such short stories are not merely a novelty. The advent of Twitter and microblogging, with its limitations on how many characters can be typed at a time, are increasingly being used to create stories.
This article by Ryan Paul in Ars Technica (Byte-sized stories: Twittering a tiny tale) attempts to list some of them. These are excellent examples of how constraints can actual foster creativity.