This article discusses the background, nature and application of the concept of ubiquitous city, presenting u-city initiatives of affluent and techno-savvy cities in Asia and the West with special reference to the case of South Korea. The focus is on how ubiquitous technologies have been and can be utilised in developing urban infrastructure, including town planning, street and property maintenance, water supply, public transportation and environmental protection. Such an emerging infrastructure is expected to provide everyone with an opportunity to access urban infrastructure and services with the help of ubiquitous technologies. However, in order to become reality, this requires some kind of democratisation of technology, which is a neglected topic in u-city discourse. It is also important to analyse u-city developments from the point of view of production of space with special reference to the potential colonisation of everyday life. Theoretically speaking, one answer to such compelling questions about the rationale of u-city development can be sought from the idea of the ‘right to the city’, a slogan originally coined by Henri Lefebvre. This approach highlights the importance of involving people to envisioning the future of urban form starting from the perspective of their everyday life. Such a dimension should be given more prominent role in current u-city developments.