1. A method of programming a memory cell comprising a pair of opposing conductive electrodes having resistance switchable material received there-between, comprising: applying an electric field through the resistance switchable material in a prevailingly laterally oriented direction to cause mobile dopants within the resistance switchable material to move laterally toward or away from one of opposing lateral edges of the resistance switchable material to change resistance between the pair of electrodes, the opposing conductive electrodes of the pair being pulled to substantially the same voltage during said applying.