In this paper we discuss personal data management with mobile devices, an activity requiringthe composition of services offered by standard suites of applications. We propose a data modeland an interface model that allows users to define activities, tasks and services, to navigateamong them according to the evolution of the personal situation as perceived and interpretedby the users themselves. The interface model acts as a lens exploring the situation, zooming intothe details, covering different areas of the personal data, supporting the user in the role of acomposer of personal services.