Has anyone tried Twitter fiction?

[Spanglish]

Has anyone tried their hand at twitter fiction? Basically, you have to write a story in just 140 words. There's something quite appealing about having to fit a middle, a beginning and an end in a single tweet. There is a website called //www.wordhorse.co.uk that has a competition on at the moment called the Whodunnit story challenge. I was thinking of giving it a go. Does anyone have any advice ?

Marta