This paper reports from an initial stage of a Swedish project concerning mobile IT support for tourism. From three workshops with actors within the tourism sector we identified barriers and challenges in designing IT support for all phases of the tourist life cycle. Thereafter we designed and evaluated a mobile tourism guide in real life setting with six different user groups. The research question of this paper is: What factors influence the design of mobile services to be used by multi-users in multiple contexts? The initial findings show that indeed there are several design challenges regarding e.g. a) the visibility of the content of the screen when multi-users are simultaneously using the service, b) the audibility of the speaker voice in the service when used in a surrounding with traffic noise, c) providing optional designs for different context, i.e. indoors/outdoors etc, and d) providing personalization options for different group sizes.