In this chapter we attempt to review the potential for the application of the spin crossover (SCO) phenomenon in various domains, such as molecular electronics, data storage, display devices. It is evident that SCO properties, such as room-temperature working range, chemical stability, low addressing power, short addressing time, full reversibility, are of promising value in the context of the stringent limits necessary in the future development of information technology, due to the unceasing miniaturization of the components. Of course, many requirements must be fulfilled before any use in a genuine device becomes feasible. Some of these are emphasized and discussed here. Additionally, this review reports recent progress in non-linear optics and photomagnetism of SCO materials.