We are developing wearable devices as the foundation for a consistently present and highly available body-area mHealth network. Our vision is that a small device, such as a bracelet or pendant, will provide the availability and reliability properties essential for successful body-area mHealth networks. We call this class of device computational jewelry, and expect it will be the next frontier of mobile systems. We prototyped our first piece of computational jewelry, which we call Amulet, to enable our previously proposed vision. It runs applications that may collect sensor data from built-in sensors or from other devices, analyze and log the data, queue information for later upload, and interact with the wearer. Independent developers can develop applications that can be vetted and installed on an Amulet.