The Electronic Necklace demonstrates that sensors can be responsive and interactive devices, even without a computer. The necklace is activated mechanically, without batteries or electronics, simply by the user playing with it. For example, turning one of the beads turns all the beads. If the user turns on an LED, the necklace will light up. It can be illuminated in various ways depending on how the beads are turned. The necklace can also be augmented to include sound, so that the beads squeak when turned. This project sets a baseline for other work in context-aware computing, where sensors and computers with memory are used to add explicit task, system, and user models to objects in our everyday environment.