I entered a book cover 'competition' on 99designs...
On 99designs different designers upload their designs and the competition holder chooses their favourite design after a certain amount of time. I'm not too sure what to think of that website- a lot of time can be wasted and the pay off isn't huge.
I didn't win unfortunately and these kind of competitions are okay for students (like me) or designers who aren't quite full time yet, but I am thinking it kinda de values the industry.
Anyway, I'm happy with how it turned out considering I only spent a day on it!
You can judge for yourselves and see the (depressing) winning design on there - http://99designs.com/print-design/contests/book-cover-needed-middle-grades-mystery-adventure-novel-102249