From very early accidental discovery of the Magnetophosphene and the linearization of Bang-Bang control in a magnetically measured, thyratron controlled, super thermostat, through several years of developing the MAD (Magnetic Anomaly Detector) for locating submarines from low flying aircraft, to a term as chairman of a special Navy sponsored ELF committee to determine whether extremely low frequency electromagnetic fields have biological consequences, to the development of vector magneto electrocardiography requiring measurement of microgauss fields produced by heart muscle action currents, I have repeatedly found myself drawn, not too unwillingly, into development of specialized magnetic or electromagnetic instrumentation, measurement or theory. Several times a basic concept developed in one project has been reincarnated years later into a very different application. I shall review several of these developments, especially where they are newly useful and not widely understood, and shall introduce some of the current studies and rather wild speculations regarding the confirmed and merely suspected biological effects of magnetic and electromagnetic fields on living systems.