Devices constructed from thin polymer films with randomly dispersed liquid crystal droplets (PDLC films) are reviewed. PDLC films have already been researched in some detail and materials in the form of tough flexible films are available commercially. The materials used in their manufacture are available in commercial quantities and can be processed by standard film-forming techniques rendering large-area, environmentally robust displays and light shutters easy and inexpensive to manufacture. Single-piece light valves of up to 3 m2 are relatively common. PDLC shutters do not require polarisers, so that light loss through the cell in the clear state is reduced. The article describes the operating principle of PDLC films and discusses their electro-optic properties with emphasis on their influence on device performance. Finally, an assessment of present and future applications of this technology is presented.