Textile seems cool. I can do stuff like emphasize words, though my favorite /italics/ markup doesn't seem to work. But, say, I want to talk about something that's copyrighted(c). I can do that. Neat-o. Oh, and
Easy. Though doing the html for headers is pretty easy, too. Hmm, a lot of neat stuff to get used to, if I'm gonna go this way. But it seems pretty powerful, easy, and unobtrusive. Thumbs up.
editor's note: since moved to Markdown Extra