Get Off My Internets has Project Wonderful ad space available. Thought I'd pass this on here because I love GOMI, I've done advertising with them before and I've always gotten great results. Their ad space easily gets over 28,000 impressions a day, but they tend to have trouble because they don't want ugly corporate ads.
Naturally I told them PW was the way to go because of all the cool webcomic/webfiction people there. So now I want to bring this is your attention so that I don't end up looking like a liar Go get it while the bidding is still dirt cheap!