Logic circuits based, at least in part, on use of spin-torque transfer (STT) to switch the magnetization—and hence the logic state—of a magnetic material are disclosed. Aspects of the invention include novel STT-based switching devices, new configurations of known STT-based devices into useful logic circuits, common logic circuits and system building blocks based on these new devices and configurations, as well as methods for inexpensively mass-producing such devices and circuits.