There is a brilliant article on Core77 on engagement and the design process by Robert Fabricant where he questions the role of design and participation in tackling important issues. He sites some excellent examples such as Project H where 'user-centred' design approaches are integral to their work in developing countries.
For example, there are principles from the social sciences, like Social Proof, exemplified by the smiley face on a utility bill which has been shown in studies to motivate people to reduce energy consumption by 20%. This does not come out of the traditional design playbook."
Folks like John Thackara have been calling our attention to this for some time: "It's about groups, communities, neighborhoods in which you have the capacity for a community to investigate and invest in solutions rather than individuals."
Participatory Design has been an accepted practice for some time now. When applied to communities, it implies a change in roles between the designer and the user, as observes: "Social innovation in the age of networks is a process of change where new ideas are generated by actors directly involved in the problem to be solved."