If you're up for entering a weekly writing contest, you can find some very interesting challenges over at TheProse.com here. Here's the current challenge:
"Prose Challenge of the Week #23: Write a haiku about deceit. The winner will be chosen based on a number of criteria, this includes: fire, form, and creative edge. Number of reads, bookmarks, and shares will also be taken into consideration. The winner will receive $100."
From what I see on the website you must first register and join their community to enter a challenge, but there appears to be no fees involved. Entries are posted on the website, along with the number of entries received, so you can read all your the competition before submitting your own (here are all the entries for the current challenge.) There are also challenges posted by the community as writing prompts, and most of those looked quite inspiring, so it appears you'll be hanging out with a very creative group of writers.