The paper presents an exploration of service design from the point of view of activity theory. The analysis in the paper builds upon recent work in service design (e.g., Holmlid, 2007; Sangiorgi, 2009; Wild, 2010), and extends our own previous research, in which activity theory was applied in analysis and design of interactive artefacts (Kaptelinin and Nardi, 2006; Uden and Willis, 2001). The discussion in the paper focuses on how services are integrated into customers’ activities. We argue that activities supported by services represent a special type of human activity: they are both collective (since they are performed by several actors) and individual (since their structure is primarily determined by the hierarchy of goals of one actor, i.e., the customer). According to the position, advocated in this paper, services can be considered as delegated actions. We tentatively identify a set of issues that need to be taken into account in service design, namely: core vs. auxiliary actions, poly-motivation, complex mediation, dynamic social distribution, whole life-cycle support, and long-term appropriation.