Why wear a computer? The broad aim of this talk is to consider the pros and cons of wiring components in a wearable system, over and above considerations of data transmission and power distribution. Over the past dozen or so years, the concept of a computer that can be worn and (more importantly) interacted with while the wearer carries out their everyday activities, has been explored and developed through many academic, commercial and military settings. In this talk, three aspects of wearable computers are explored in terms of the impact of, and need for, wiring: (1) attachment (computer worn on body); (2) mobility (access to communication/processing/information/data/people while mobile) and use while hands/eyes are busy; (3) attention (maintaining attention on the primary task. Also discussed are awareness and adaptivity (responding to changes in environment/context), modifying information to suit the person; and (ultra) personal computing which adapts to the wearer.