I came across this Coworking group on flickr. Its called Citizen Space, located in San Francisco and it seems to be a great example of the of this kind of cooperative workspace. The group maintains its own website where they explain their office culture and policies.
The idea of Citizen Space is to take the best elements of a coffee shop (social, energetic, creative) and the best elements of a workspace (productive, functional) and combine them to give indie workers the chance to have their own, affordable space. Citizen Space was built on coworking philosophy.
In some ways they have an even better description of what the Coworking philosophy is all about. If this idea intrigues you, or you aspire to set up such an office space their site is a worthwhile read. Several members of Citizen Space have flickr accounts and you can find photos from many of their events posted there to get a feeling for their community. And here is a short video about the Coworking idea that they have on their site: