Postcard Shorts is an excellent little website that I stumbled upon only recently. The idea behind it is that any story must be able to fit onto a postcard, i.e. be only about 250 words in length.
After being reviewed by a panel, the best stories are then published.
Here's the link to mine, which is titled 'Stage Fright.'
After being told it had been accepted, I received this rather excellent tweet!