This paper proposes Spinning Sensors, a middleware system for creating robotic sensor network applications. This middleware enables application programmers to easily write application software which utilizes both sensors and actuators in their network. In the Spinning Sensors model, a sensor node is attached to a robotic actuator to change its position and/or direction. The continuous position change enables the single robotic sensor node to cover greater sensing area and sensing time. This paper describes robotic sensor node model that the sensor and the actuator are attached together as one node, then present our design and implementation of the software which achieved both versatility and functionality simultaneously. We constructed three applications using the middleware: an environment monitoring, a radio control robot, and context-aware services. We show the result of experiment in which we utilized multiple robotic sensor nodes to monitor the environment.