Facebook's Monthly iPhone Photography Contest

Facebook sets a monthly challenge for you iphone shooters and has a dedicated page for this.  Not really sure about what the prizes are but it sounds like a lot of fun.  Here is the link and the rules are below:  FACEBOOKIPHONECONTEST
The Rules

The competition will last for 1 month at a time.  Add your photo then right 'Vote' on other photos. The more votes will win the competition, as it's just a fun competition. There are no prizes, but you will be chosen to pick the theme for the next competition. Good luck! • iPhone Photos only!