You might try a press release.. There was some talk over at DP of Google giving the 50 penalty to people who use specific (unnamed) press release services though.. so be sure to look into that.
You can ask forum owners to allow you to post (or post with for you) details, but for the most part they’re probably going to want their traffic to use their banners, which doesn’t really help you to much.
Other out of the box ideas.. that aren’t nessisarily free include:
ReviewMe.com you could find a bunch of related blogs, have the owners of the blogs post an announcement of your tournament.
SponsoreredReviews.com PayPerPost.com same thing. Target high traffic blogs, well known blogs, and then blogs with decent alexa rankings, and blogs that are indexed in Google Blog Search, blogs with a lot of comments might be good as well, at least you can tell there’s activity.
There are actually a couple lil radio podcasts majiggy’s I’ve been meaning to listen to for sooo long, and I hate to say, i don’t know if they’re for players or affiliates, but the ones for players.. buy a commercial?
Thats my brainstorming for now..
Good Luck 