I've seen this talked about here and there on the 'net but thought I'd post a link to Hell Notes where they have the top ten really short scarey horror stories. The writer has two sentences or less to scare the crap of readers :) Can you do that? If you'd like to give it a whirl drop your story in the comments here. Have fun!!
Here's my try:
The middle of freaking nowhere and the pickup sputtered to a stop beside a creepy looking old man smoking a cigarette. Too bad the gas tank was full.