Various embodiments of the present invention include three-dimensional, at least partially nanoscale, electronic circuits and devices in which signals can be routed (1016) in three independent directions, and in which electronic components can be fabricated at junctions (510, 802) interconnected by internal signal lines ( 502-509 and 702-709). The three-dimensional, at least partially nanoscale, electronic circuits and devices include layers, the nanowire or microscale-or-submicroscale/nanowire junctions of each of which may be economically and efficiently fabricated as one type of electroniccomponent. Various embodiments of the present invention include nanoscale memories, nanoscale programmable arrays, nanoscale multiplexers and demultiplexers, and an almost limitless number of specialized nanoscale circuits and nanoscale electronic components.