The Writer's Bureau is running a short story contest until the end of June. There is a small entry fee--5 pounds (unless you're already a subscriber to their newsletter, then it's 4 pounds). FYI--Paypal will convert your currency for you, so you don't have to stress over the monetary figures. And 5 pounds is just over $8 American.
The prize for winning this contest is 500 pounds, which is $817.44 in American dollars.