The study of “Smart Dust systems” is very new. The main purpose of this paper is to present some of the technological opportunities and challenges, with the goal of getting more systems-level researchers interested in this critical area. The remainder of this paper is organized as follows. Section 2 presents an overview of the technology that underlies Smart Dust. Section 3 outlines the key networking challenges presented by this technology. In Section 4, we describe some of the potential applications of Smart Dust and the challenges they pose. Section 5 discusses related projects from the research community. Section 6 presents our summary and conclusions.