Embedded systems are dedicated computers designed to perform a specific task. They are usually fairly simple devices that are used in areas where powerful, customizable computers are unnecessary; however, they can also be quite complex on occasion. Embedded systems can be found almost anywhere, including automobiles and cellular phones, and their importance is reflected in their near omnipresence. An excellent introduction to embedded systems can be found in the first three pages of this online course material (1). The educational module gives a thorough definition of embedded systems, several examples of where they are used, and a discussion of their common components. For a more detailed explanation of how these devices are used to control various appliances, motors, and other real world products, this site (2) is worth a visit. Sixteen sections comprise the site, and each includes background information and an example experiment. Although certain equipment is required for the experiments, much can be learned simply from reading the introductions. This enlightening essay (3) documents the history and development of embedded systems. Despite being somewhat specific to the author's life, it effectively illustrates the evolution of embedded systems and their incorporation into many facets of everyday life. A paper presented at the 2003 International Cryptology Conference (4) considers the vulnerability of embedded cryptosystems to side channel attacks, which are different from normal security violations because they involve monitoring parts of the hardware system instead of the software. The authors propose the design of private circuits that are resistant to such attacks. The Center for Robotics and Embedded Systems at the University of Southern California is the source of this paper (5) about networked robots. Although it is somewhat dated, the paper provides some valuable insights into how robots can be used in human environments and how they can be controlled and coordinated with wireless communications. An article from Dedicated Systems Magazine (6) highlights the role of embedded systems in NASA's Mars Exploration Rovers, which were launched in June and July 2003. The technologies that enabled the rovers to have powerful, reliable operation are described. The April 2003 issue of ACM Queue (7), the online magazine of the Association for Computing Machinery, is dedicated to embedded systems. Seven articles are included in the issue, dealing with the design and construction process of embedded devices and the hardware/software interface. Lastly, a short paper that was presented at a computer architecture symposium in January 2003 looks ahead to the realization of ubiquitous computing (8). This technology revolution, which has been predicted for many years, promises to make tiny computers embedded in virtually everything, even clothing and walls. The author focuses on the area of intelligent vehicles and wheeled mobile robots.