While tourism presents considerable potential for the use of new mobile technologies, we currently have little understanding of how tourists organise their activities or of the problems they face. This paper presents an ethnographic study of city tourists’ practices that draws out a number of implications for designing tourist technology. We describe how tourists work together in groups, collaborate around maps and guidebooks, and both ‘pre-’ and ‘post-visit’ places. Implications are drawn for three types of tourist technology: systems that explicitly support how tourists co-ordinate, electronic guidebooks and maps, and electronic tour guide applications. We discuss applications of these findings, including the Travelblog, which supports building travel–based web pages while on holiday.