This chapter presents a brief discussion of how pattern recognition, signal feature selections, pattern tracking, and automated network architectures are functional blocks of a smart sensor system. Extensible markup language (XML) is ideal for organizing the information from intelligent sensor networks. The sensor data in XML can support a live web page with meters and gauges for the sensor raw data or processed information, and it can feed network-based programs for hierarchical information processing. Consider a civil defense application regarding a fire evacuation scenario where there are sensors for wind, temperature, smoke, traffic, and access to databases for traffic, topography, and recent weather patterns. The chapter explores a new area for intelligent sensor systems: prognostics. Prognostics is the ability to predict a logical outcome at a given point of time in the future based on objective measures of the current and past situation.