You reddit right: the moderators of /r/Screenwriting on reddit are hosting a screenplay contest. Submissions close at midnight, March 31st. Feature-length scripts only, to be judged by a panel of industry experts (also, they are looking for judges, so if you or someone you know is an industry expert, sign up!).
Perhaps the best part is that this contest is FREE TO ENTER, and there are multiple ways to contact the administrators with questions. There will also be an AMA on the site soon to address the competition specifically. So send in your work already!
The winner will receive a free pass to the Great American Screenwriting Conference & PitchFest as well as the honor, nay, the glory, nay, the imperial right of calling him or herself The Winner Of The Reddit Screenwriting Contest. Runner-ups will receive prizes from Shore Scripts, a coverage service that also runs a screenplay competition. Full rules and regulations here.
To be clear, this is NOT an official reddit contest. This is being put together by the moderators of /r/Screenwriting, and is not being run by reddit administrators.