Ficlets

Short Story mashup site from AOL. Ficlets.com was created by Kevin Lawver and a small AOL developer team over a few months of work.

Once you've written and shared your ficlet, any other user can pick up the narrative thread by adding a prequel or sequel.

http://ficlets.com/

Les Orchard made an RSS feed combining an authors stories, prequels/sequels, and comments.