No idea is entirely new, after all. Here are some similar interesting sites:

Quickmuse
Watch poets compose in fifteen minutes.

Six Fics
Stories told in six freakin words.

One Sentence
Stories told in a single sentence. Addictive.

Two Sentences
Choose one sentence, then oppose it.

First 50 Words
50-word tales on a single prompt.

400 Words
Short-short nonfiction.

Ficlets
A wiki-like site of 1024-word stories.

PostSecret
Confessions that fit on the back of a postcard.

Crunchable
First dreams are the most vivid.