A free online library where members can publish documents. The terms say not to upload marketing material, like the rebranded ebooks that lead to completely idiotic Web sites that have the function of selling more of the rebranded eBooks. But, from what I could see submitting a free short story, or an eBooklet with tips for authors is fair game. An example is Paperback Writer Lynn Viehl's free stories and writing tips. Another non-fiction author Bill Allin has set up a group highlighting his work.
There is a social network involved where people can "friend" other members, join and create groups, and comment on each other's writing, or label their work as a favorite.
There are tons of public domain free eBooks from short stories to novels.
You might already be a "member" because members can use their LiveJournal or Technorati ID (among other options) to sign up.
See Also: http://www.squidoo.com/promoteyournovel (Free & Low Cost Promotion of Your Romance Novel)