In this paper, we describe the process behind the design of Audio Aura. The goal of Audio Aura is to provide serendipitous information, via background auditory cues, that is tied to people's physical actions in the workplace. We used scenarios to explore issues in serendipitous information such as privacy and work practice. Our sound design was guided by a number of strategies for creating peripheral sounds grouped in cohesive ecologies. Faced with an physical and software infrastructure under development in a laboratory distant from our sound studio, we prototyped different sonic landscapes in VRML worlds. In our infrastructure design, we made a number of trade-offs in our use of legacy systems and our client-server design.