unblokt is my first attempt at social software. To get an idea as to how unblokt works, consider the 200-page novel that is currently being written. A visitor to the site is presented with a random sentence from the novel and the one following it. The task is to write a sentence between these two. However, these 3 sentences are not "locked" together. At random, any of them may be presented to other users, who may then stick more and more sentences between them. Kind of like a "Big Bang" for writing. I am informed by Matt Obert of the Verbatim writing group that the writing method implemented by unblokt is in fact quite old, and is termed larding.
At this time, random people on the web have written
a 300-page novel,
a "Dear John" letter,
a "George W. Bush" speech,
a "Letter from Camp",
about 100 pages of a second novel,
and a few scattered sentences in a number of other genres
These can be read on the unblokt bookshelf. A word of warning: some authors have chosen to write some fairly racy sentences, so be prepared. I hope to soon make unblokt both social AND democratic by allowing the community to vote offensive sentences or spam "off the island", so to speak.