We describe the design of a compact, wireless sensor module meant to capture expressive gestures in real-time when worn at the hands and feet of a dancer. Each sensor node includes a 6-axis inertial measurement unit (IMU) that contains three orthogonal gyroscopes and accelerometers in order to capture local dynamics, as well as a capacitive sensor to measure node-to-node proximity. The nodes are designed to be easily augmented with other digital or analog sensors. The onboard radio transceiver supports a power-efficient, high-speed RF network capable of real-time data acquisition from several devices simultaneously, thereby meeting the requirements of instrumenting a small dance ensemble for interactive applications. This paper describes the application goals, presents the prototype hardware design, introduces concepts for feature extraction, and shows early test results.