"The concept of stigmergy has been used to analyze self-organizing activities in an ever-widening range of domains, from social insects via robotics and social media to human society. Yet, it is still poorly understood, and as such its full power remains underappreciated. The present paper clarifies the issue by defining stigmergy as a mechanism of indirect coordination in which the trace left by an action in a medium stimulates a subsequent action. It then analyses the fundamental components of the definition: action, agent, medium, trace and coordination. Stigmergy enables complex, coordinated activity without any need for planning, control, communication, simultaneous presence, or even mutual awareness. This makes the concept applicable to a very broad variety of cases, from chemical reactions to individual cognition and Internet-supported collaboration in Wikipedia.
Mark Elliot of Collabforge wrote his thesis on Stigmergic Collaboration: http://mark-elliott.net/blog/?page_id=24
Maybe the issues cities like Melbourne have providing infrastructure to serve developer-led growth suggests a limit to what can be achieved without more widely grounded strategic planning taken out of the hands of politically volatile interests.