1. A nonvolatile memory cell comprising: a switchable resistor memory element; and a thin film transistor having a channel region, wherein the switchable resistor memory element is disposed in series with the thin film transistor, wherein the switchable resistor memory element decreases resistance when a set voltage magnitude is applied across the resistive memory element, and wherein the switchable resistor memory element increases resistance when an reset voltage magnitude is applied across the switchable resistor memory element, and wherein the polarity of the set voltage magnitude is opposite the polarity of the reset voltage magnitude.