I don't like the concept of having my story voted on by people who aren't writers. These open contests on commercial websites aren't meant to promote the best writers but rather the ones who can get the most people to "friend" them. You can actually win a money grants this way by getting the most people to vote for your idea. The contests I detest the most are those where you have to post your entry on Facebook. That way the advertiser can get access to all your friends to post their advertisements.
If you'd like to enter a fun contest, here's one I like...It's from Black Lilac Kitty with an April 1 deadline.
The story must include a cat and a Rottweiler. The Rottweiler cannot be a "mean" dog. The cat and Rottweiler can belong to the same person or have different owners. Somewhere in the story must be the phrase "it was a dark and stormy night." The word count must be at least 2,000 words and no more than 7,000 words. For complete details click here.