Piezoelectric materials are opening the door for the design of large smart structures. To explore what possibilities there might be for building practical smart structures, a review of the characteristics and methods of processing piezoelectric active materials is given. The advantages and limitations of using the different forms of piezoelectric materials for sensors and actuators are then discussed. One area where piezoceramic sensors can have a large impact is structural condition monitoring. Structural condition monitoring refers to using in-situ sensors to monitor the internal loads and the health of a structure in real-time. This will allow a structure to be operated at its maximum performance and efficiency while minimizing the fatigue damage. To achieve this on a large structure, a new highly distributed sensor concept is discussed in which piezoceramic fibers and microelectronic components are used to mimic the biological nervous system. A simplified simulation and experiment are presented to show how this artificial neural system can measure dynamic strains and acoustic emissions caused by damage in structures.