I don't share a lot of writing contests here, simply because there are so many. But this one struck me as kind of unique and more geared toward working freelance writers.
Copyblogger is having a short-essay contest with the prompt Why It's Important to Be an Online Authority Today. Two caveats: the prizes are trainings and memberships in one of Copyblogger's learning groups called Authority Intensive (i.e. as opposed to cash), and the deadline is today.