When thinking about the discussions that occur in social networks, when topics are thrown up for discussion on a blog or microblog, crowd sourcing just doesn't give justice to the expertise, kinship, and heart that is woven into the conversation. I have experienced several crowd sourcing events in the online socnet space that are taken up a notch to community sourcing.
I picture a table of friends discussing a topic of interest when I think of community sourcing. Warren Sukernek, @warrennss, helped me with the following community sourcing defintion:
Community sourcing is taking crowd sourcing to the next level: Outsourcing a task to a connected group of people for the benefit of that group.