Janine:
May I suggest using the "Storyboard" feature for collaborative writing, which is already in place in the library? Click on the tab with that name (located between Lucky Dip and Audio). It allows you to start a new story and then have other writers add/respond to it. (Once there, read the "Help" section to get an overview of how it all works). Perhaps just make an announcement in the forum telling interested readers/writers to check that location for the letters in progress.
Spot on, Janine. The forum has never been intended as a vehicle for publishing stories or ephemera. The storyboard is designed for collaborative writing and will be just the thing for what Goodgulf is suggesting.