The UbicompGC initiative is a response to the momentous developments occurring in the world around us, which represent a shift from 'visible' to 'invisible' computing. The phenomenon is best known as 'ubiquitous computing', first identified as a trend by Marc Weiser in 1988, but is also referred to as pervasive computing. We are already witnessing a huge increase in the numbers of miniature computing devices-almost imperceptible, but often globally connected and everywhere around us-embedded in smart buildings, shops, vehicles, environment, clothing and even implanted in the human body. They are used to control processes, monitor the environment and our health, and communicate with others and other devices, in learning, fun, business and intellectual endeavour, at home or during travel. Our interaction with them is an extension of normal everyday activities. In the words of Adam Greenfield (Greenfield 2008), these items of technology (RFIDs, short-range wireless, sensors) are 'everyware' (Greenfield 2006), offering seemingly endless opportunities to spearhead technological innovation and commercial development.Clearly, ubiquitous computing has enormous potential, but how well do we understand the full implications of its widespread adoption? Ambitious exploitation proposals are often met with concerns, from both ordinary citizens (Can I trust the mobile phone access to online banking service? Is the chemical pollution sensor reliable? How do I know that the on-body sensor is safe?) and system designers and developers (How best to coordinate a wireless network consisting of a multitude of devices? What theories can help in ensuring