Functional jewelry is disclosed. A bracelet includes a plurality of light-emitting diodes (LEDs), a main control unit, and positional and situational sensors, typically including an accelerometer, as well as a decorative, interchangeable fascial layer. The bracelet may also include sensors such as capacitive touch sensors, a microphone, and a color sensor. A radio transceiver within the bracelet is adapted to implement a protocol such as BLUETOOTH® 4.0, and is adapted to allow the bracelet to communicate in peer- to-peer or master-slave mode. Two users can pair their bracelets in person, usually with a gestural trigger, for shared light displays, multi-player games, and other types of interactions. Larger groups can pair temporarily and contextually for multi-user displays and interactions, in an ad hoc network with distributed functions. Real-world interactions are communicated to a social network with profiles linked to the individual bracelets.
