This paper reports design requirements derived from an ethnographic fieldwork on road inspectors, the design of a mobile service supporting infrastructure management, and initial user feedback. Seeing that the road inspectors are truly mobile, acting in vast settings full of objects with variable status, they lack overview of their upcoming tasks. The PlaceMemo prototype allows them to place geographically coupled voice annotations in their work setting. The voice memos are played through their entire length before reaching the precise position of the recording, and are also accessible when being geographically distant. By handing out the prototype to a number of users, we successfully demonstrate that this lightweight context-aware system facilitates their mobile work. They obtain an overview supporting the advance preparation of inspection tours, and can easily access earlier recordings while driving, in order to be reminded and to prepare stops in time.