Um...ew. Close your coat. It's not that kind of flash.
The lovely writers of Flashy Fiction are hosting a fun contest all through October. Just enter a comments section (of any post, I believe) with a short short story, and you are automatically entered in a drawing to win a $20 gift certificate to Amazon on November 1st!
And if you've never visited, hang around. Every day, one of the writers posts a prompt of some sort – picture, phrase, headline, etc – and challenges you to write a piece of flash fiction in the comments section. Very fun!
And, seriously...the coat.