Three guys from SF hackin some nice things.
Write Something is a simple collaborative writing game. Write a line and wait for someone to write the next one. Then, share your creation with friends.
There is no score or winning or losing. The rules are only defined by the type of poem you choose to write, and your own imagination.
Chrome and Firefox only (Chrome is best).
Login with Facebook/Twitter (or create a Write Something account if you prefer). NOTE: Some users may experience errors logging in with Twitter (just try a different auth method).
After that, go to the poems page and either click on a poem or start a new one.
Each poem has a different type of rule (for example, haiku has standard haiku rules, three word is a game where you write a poem three words at a time).
Invite a friend to your poem page to collaborate with you. You should see their submissions live. 
Sidenote: The internet is already full of negative prose, so let's try to be kind to each other in Write Something. :)
 As of NKO finish, Nodejitsu was having latency issues due to tons of NKO deploys, which can cause very large socket timeouts and make the live submissions not work. Try coming back later or refresh the page.
GeddyJS, socket.io, Twitter Bootstrap (with Glyphicons), ShareThis, Facebook and Twitter OAuth (via geddy-passport), Lots of Regex, MongoDB (via MongoLab).