For last week's prompt, I used a contest I'd entered on the site Furious Fiction. 500 words, in 55 hours, for a $500 prize. This month the criteria were to include a train, frozen, and three consecutive three word sentences. I sent mine in last weekend, and the results will be announced July 24. Mine was 489 words. It was initially 600 or so, then I pared it down.
Update - here's the results - winner, short list, and long list. I'm not there - oh well. I'll keep writing. They had over 1200 submissions for this one.