In addition to the miniaturized sensor nodes, Wireless Sensor and Actor Networks (WSANs) employ significantly more capable actor nodes that can perform application specific actions to deal with events detected and reported by the sensors. Since these actions can be taken at any spot within the monitored region, the actors should strive to provide maximal coverage of the area. In addition, minimizing the time to decide which actor should take what action is of utmost important for responsiveness. In this paper, we propose a distributed actor positioning and clustering algorithm which employs actors as cluster-heads and places them in such a way that the coverage of actors is maximized and the data gathering and acting process times are minimized. Such placement of actors is done by determining the -hop Independent Dominating Set (IDS) of the underlying sensor network. The performance of the approach is validated through simulations.