For solving complex problems, the authors advocate constructing \"Social computers\" which combine software and human services. However, to date, human capabilities cannot be easily programmed into applications in a similar way like software capabilities. Existing approaches exploiting human capabilities via crowds do not support well on-demand, proactive, team-based human computation. In this paper, they explore a new way to virtualize, provision and program human capabilities using cloud computing concepts and service delivery models. They propose novel methods for modeling clouds of human-based services and combine human-based services with software-based services to establish clouds of hybrid services. In their model, they present common APIs, similar to APIs for software services, to access individual and team-based compute units in clouds of human-based services.