I just discovered Ashoka a well-established organisation working in the social sector -actually been around since 1980 (!) driving for local change with a global network. Causes is bringing societal responsibility to social networking by creating applications for Facebook and mySpace.
The world is getting flatter every day -- but it is also retaining the uniqueness of acting local. Flatness and "localness" represent different dimensions. I think one represents access to knowledge and tools while the other represents the actions and solutions. Access speeds up action... I think.