Flash fiction is a good exercise in being concise. I've a number of flash fiction pieces published from as few as 75 words at Paragraph Planet to around or over 1000 -- the definition of flash varies by publisher, although I tend to think of it as under 1000, closer to 500. There have been some very good short stories of around a thousand words.
I've two short pieces available to read online from Shotgun Honey:
