Note: I wrote this up a couple of days ago, hit publish, and walked away assuming it had done so. Turns out some glitch meant it hadn't. So now the deadline is this evening, but my thoughts on the contest remain the same. Do keep your eye out for it next September/October and think about signing up. You have to sign up before the first round is announced if you want to join in.
Last year and this year I've had fun participating in an online contest called Wyrm's Gauntlet. It's a four-round, elimination contest that spans roughly two months (if you make it all the way to the end). Last year I did the first three rounds but missed out on the fourth--the winnowing is pretty intense, so by the time you get to round three, there are only five or so participating, and only three of those five make the final round.
They've hosted some fun, unconventional tasks for the contest. All writing related, but some are more focused on critiquing or reviewing works (by others or even by yourself), showing that you're able to think critically about writing. So it creates and odd but well balanced competition, which was a good way to push myself.
This year I made it to the final round and am really pleased with the story I turned in the other day. Can't wait to hear the results after Saturday's deadline (not sure exactly when they'll be announced, but probably a couple days after that). Wish me luck. But mostly I'm just glad to have been able to participate in all the rounds.