This paper presents a case study on the iterative design of a system for delivering in-situ information services to users’ mobile devices using proximity-based technologies. The design advances from a questionnaire study of the users’ attitudes and needs toward such information services via several incremental prototypes evaluated in a usability lab and at a university campus to the final version subjected to longitudinal evaluation "in-the-wild" in a city center. The final prototype is a hybrid interface where the users can select from an interactive public display the information services to be downloaded to their personal mobile devices over no-cost Bluetooth connection. The results include an empirical comparison of different models for delivering such information services, and a quantitative analysis of the usage of the system by the general public over a period of 100 days. Our findings suggest that multiple environmental factors strongly affect the usage of the system. Furthermore, the usage varies distinctly between different contexts, and there is a strong correlation between location and usage patterns. Finally, we present a number of guidelines for designing and deploying this type of hybrid user interfaces.