Giveaway wireless sensors for large-group interaction

We have developed a small, handheld or wearable, wireless motion sensor that sends out a short RF pulse whenever it is jerked. The hardware is minimal, as it mainly includes only a piezoelectric foil accelerometer, a CMOS timer, and a single-transistor 300 MHz RF transmitter. As such, the onboard battery should last for many years, and the cost is low enough (well under US $1. in large quantity) to be given away with a ticket to an event, enabling it to be used to allow individuals to contribute to a large-group, real-time interaction. We discuss results from experiments using this device to explore collaborative music control, and touch on other applications.