"Social innovation is a process of change where new ideas emerge from a variety of actors directly involved in the problem to be solved: final users, grass roots technicians and entrepreneurs, local institutions and civil society organizations. The main way in which it differs from traditional “garage” innovation is that here the “inventors” are groups of people (the “creative communities”) and the results are forms of organization (the “collaborative services”).
Looking attentively to the complexity of the contemporary society shows many cases of these worldwide (for more, see the Sustainable Everyday project). While the stories are diverse, they have one clear (and expected) common denominator: they resulted from the initiatives of people who collaboratively invented new ways of living and producing and who have been able to enhance them, solving specific problems and, at the same time, making concrete steps towards sustainability happen.” (http://www.experientia.com/blog/designing-for-social-innovation-an-interview-with-ezio-manzini/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+PuttingPeopleFirst+(Putting+People+First)&utm_content=Bloglines)
"An initiative, product or process that profoundly changes the basic routines, resource and authority flows or beliefs of any social system. These social innovations have broad impact, durability and scale; and also have recognizable stages and phases linked to the dynamics of resilient systems.
In other words, social innovation or transformational social change, should have the capacity to impact a broad number of people on an ongoing basis, scaled across multiple sectors and communities spread apart by large geographical distances, and can adapt and respond to massive change while still maintaining the integrity of the original. It is important to note that I use the word resilience instead of sustainability in this case, as resilience is about having the capacity to adapt to change, whereas sustainability, focuses on maintaining a stable state at any scale." (http://www.renjie.ca/opportunities-to-create-social-change-worksho-0)
About the multiple definitions
The Wikipedia writes at http://en.wikipedia.org/wiki/Social_innovation :
"Over the years, the term has developed several overlapping meanings. It can be used to refer to social processes of innovation, such as open source methods. Alternatively it can be used to innovations which have a social purpose - like microcredit or distance learning." (http://en.wikipedia.org/wiki/Social_innovation)
In the P2P Foundation literature, we use it almost exclusively in the first sense. Saying innovation is or has become social, means stressing that innovation is an emerging property of distributed networks. It is located in the overall community and ecology, and less and less exclusively within an institution or from a single individual entrepreneur.