Six Sentences is a place to publish just that: six sentence stories.
It has been one of Writer’s Digest’s 101 Best Sites For Writers and publishes a new six-sentence story every day. It’s a great (non-paying) market for flash fiction writers.
It offers readers the chance to vote the story “good”, or “spectacular” (a ratings system I love) and provides a link back to the author’s site.
Check out the writer’s guidlines here or read some recent six-sentence stories.