A significant body of evidence points to a strong relationship between those who are economically, socially and/or politically marginalised, and those who are marginalised in their access to, and use of, ICTs. The main purpose of this report is to explore and understand the role of the mobile phone in the lives of the less connected. The less connected, as identified for this report are those who, if they use the Internet at all, use it mainly or only on their mobile phones; whose home languages are under-represented online; and who largely depend on mobile operator networks for their connectivity, since they do not have fixed-line connections at home. Research sought to explore what kind of experiences of being connected these people have, and what role the mobile phone plays in their everyday lives. To do this, the authors developed a new diary interview method to construct the mobile diaries of more than 80 people in three locations in urban and rural South Africa. The diaries show that mobile phones are a vital part of these people’s lives. However, the diaries also suggest that the communication links between the less connected and the wider world are fragile, and mobile phones are used only with complex and frugal management.The diarists, if they use the Internet at all, use it mainly or only on their phones and largely depend on mobile operator networks for their connectivity. Governments, corporations, civil society organisations and activists working to use mobile phones to connect to the less connected are unlikely to succeed if they do not make more efforts to learn about, understand and then take account of their everyday practices and constraints, in South Africa and elsewhere. The Izolo mobile diaries are a contribution to deepening our understanding of the practices of the less connected in South Africa.