Adaptive filters are devices that adjust their internal structure in response to changes in the surrounding environment. In this way, adaptive filters are endowed with both learning and tracking abilities that make them extremely useful in a variety of areas ranging from communications to biomedical engineering. In recent years, the explosive interest in these areas, and in information technology, has motivated heightened research in the field of adaptive filtering. In many applied problems of wide interest, emphasis is now being placed on the analysis and design of interactive adaptive blocks within complex systems. This talk provides a few examples with an overview of recent advances in the areas of adaptive techniques for wireless location applications in cellular systems, adaptive techniques for source coding and power control in wireless systems, and adaptive techniques for human-machine interfaces and wearable computing.