Most current input devices require dedicated attention by our hands through physical transducers such as the keys on a keyboard. Similarly, computer output is dominated by visual displays requiring most of our visual attention. While keyboards and monitors are effective I/O devices for dedicated computing activities, when our primary task is not using a computer, our hands may not be free to manipulate an input device. The goal of my dissertation is to explore how on-body interfaces can better support computing in our everyday activities.