A brief review of nanowires used in electronic and optoelectronic devices that could enable diverse applications is given. Nanowire field-effect transistors, nanowire lasers, as well as crossed nanowire structures and nanowire heterostructures, are discussed. Due to the possibility of controlling the key parameters (chemical composition, structure, size, doping, etc.) on a nanoscale, these devices exhibit new or enhanced functions crucial to many areas of technology.