The term “crowdsourcing” was initially introduced by Howe in his article “The Rise of Crowdsourcing” [1]. During the last few years, crowdsourcing has become popular among companies, institutions and universities, as a crowd-centered modern “tool” for problem solving. Crowdsourcing is mainly based on the idea of an open-call publication of a problem, requesting the response of the crowd for reaching the most appropriate solution. The focus of this paper is on the role of crowdsourcing in knowledge acquisition for planning applications. The first part provides an introduction to the origins of crowdsourcing in knowledge generation. The second part elaborates on the concept of crowdsourcing, while some indicative platforms supporting the development of crowdsourcing applications are also described. The third part focuses on the integration of crowdsourcing with certain web technologies and GIS (Geographic Information Systems), for spatial planning applications, while in the fourth part, a general framework of the rationale behind crowdsourcing applications is presented. Finally, the fifth part focuses on a range of case studies that adopted several crowdsourcing techniques.

The globalization process taking place in the context of information society provides a broad range of opportunities to the actors involved in more efficient organizational forms, new trading opportunities, restructured educational perspectives, new employment challenges, etc. Employment patterns so far have been dramatically influenced by the rapidly evolving technological innovations and their potential role on spatial structuring both at the urban and regional level. One prominent application of the newly offered possibilities is teleworking which alters considerably traditional patterns of work, mobility patterns, energy consumption patterns, personal relationships, etc. While teleworking has induced new forms of work organization, technological developments have also advocated radical changes in the structure of firms, where “virtual organization” is emerging as a response to increasing competition and need for efficient use of resources. Virtual organization is characterized by three distinct elements, namely-, new organizational forms, being active beyond the limits of the traditional company model, a network function support, where various firms are trying through networking to seize business opportunities, which none of them would be able to realize on their own and the ability to overcome time and space barriers in a rapidly changing global marketplace. The focus of the paper will be to explore the new perspectives opened to spatial restructuring due to the introduction of virtual firms.