Into the flash fiction category belong a number of very fun and interesting short stories. I found a short page detailing a few of these here. I’d suggest people who are interested in these very interesting literary works to go and take a look.
I think my present favourite of these is Orson Scott Card’s “The baby’s blood type? Human, mostly.”.
However, I’ll present two issues with that site I brought up in the beginning of this post: The story of Arthur Charles Clarke is an adaption he made to a very short (31-word) short story which you can also find at this site. It is titled “siseneG”, and also recounts the story of the world.
As the second issue: that story accredited to Ernest Hemingway on that short story listing is not actually Hemingway’s but is now taken to be authored by William R. Kane as a recent investigation into the matter proved (Slate article here).
Also, Wired has an interesting list that was, I believe, written in response to their competition for very short stories (they limited theirs at six words) here. The link above has some but not all of the ones present on the Wired site.