Steve Rubel's Micro Persuasion spotlights a new "content marketplace" called Glypho. It all starts when somebody comes up with a plot idea, like "a man wakes up in the middle of the night with a searing headache...[,]covered in blood that is not his own," and then other people take the story and run with it. Then people vote on whose contribution they like best, and then everbody moves on to the next chapter, where they start the whole thing over, until they've got a novel. It's all covered by a Creative Commons license, so the stories can float off Glypho and circulate freely throughout cyberspace (and into print) whenever they're done.
The print-on-demand customer base may expand once some of these stories are completed, but those of you who are still writing in comparative isolation and only showing other people your stories at completion probably don't need to lose any sleep over the competition just yet. Actually, I'm a bit surprised that among all the story categories Glypho had listed, there's no erotica; I'd have thought the category a natural for aspiring writers online (which probably just shows the gutter my mind's in). But even the "romance" pickings seem to be pretty slim so far...