I just watched this video demo of Zembly, a relatively new service that you create collaborative applications on the fly and deploy them to services like Facebook, Meebo, and the iPhone.
It's also interesting in that the company makes use of a wide array of open APIs and developed their own to create a networked effect of usage.
In a bit of a twist, Zembly runs on Solaris and Sun hardware at Network.com. Maybe Sun is getting their cloud act together after all?
Video courtesy of Cote at Redmonk.