Stochastic sensors have been the subject of considerable recent interest as a result of their ability for reconfigurable, rapid, multi-analyte detection as well as their potential for sequencing DNA. These sensors are created by placing a nanometre-sized pore in an insulating membrane and measuring the ionic transport through the pore in the presence of the molecules of interest. The magnitude, duration, and rates of occurrence of the resultant current blockades allow rapid determination of analyte concentration as well as discrimination between similar molecular species. The bulk of the work in this nascent field has been focused on biologically-based stochastic sensors using protein pores and lipid membranes, although hybrid and completely non-biological systems are also the subject of active investigation. I review this work as well as recent efforts to extend these systems and translate them into usable laboratory and clinical tools.