1. A nerve mapping and monitoring system comprising: a multi-polar stimulation unit; a grid array of electrodes integrated onto a surface of a surgical instrument configured to be inserted into a tissue site of a patient to map locations of neural structures in the tissue site, wherein: the grid array of electrodes comprises a plurality of electrodes, each of the plurality of electrodes is configured to be individually and independently electrified by the multi-polar stimulation unit including independent control of a respective polarity and respective one or more stimulation parameters of each of the plurality of electrodes, and every one of the plurality of electrodes is configured to be stimulated as part of at least mono-polar, bi-polar, and tri-polar stimulation configurations; an electrical connector having a first end and a second end, wherein the first end is configured to be removably coupled with the multi-polar simulation unit, and wherein the second end is configured to be removably coupled to the grid array of electrodes; a computer system configured to cause the multi-polar stimulation unit to deliver bursts of electrical current to the grid array of electrodes integrated onto the surface of the surgical instrument to individually and independently electrify electrodes of the plurality of electrodes, wherein the computer system is further configured to cause the multi-polar stimulation unit to deliver the bursts of electrical current to the grid array of electrodes in a plurality of sequences using sequential stimulations of varying combinations of electrodes at different regions on the grid array to build a virtual map of locations and proximities of neural structures in the tissue site, wherein the sequential stimulations are defined by a plurality of stimulation configurations including at least mono-polar, bi-polar, and tri-polar stimulation configurations of different electrodes on the grid array of electrodes in order to produce variable electrical current densities in biological tissues adjacent to the grid array of electrodes on the surgical instrument in the tissue site and in order to enable detection of evoked potential responses from any nerves that may be located in proximity to the surgical instrument, wherein any given stimulation configuration and stimulation parameters may or may not activate nearby neural structures which may or may not produce evoked potential responses that can be recorded and analyzed with a differential amplification recording system using evoked potential recording techniques, wherein each combination of electrodes is stimulated simultaneously for any given stimulation configuration; a recording element comprising a differential amplification recording system capable of recording and digitizing a brief epoch of time following each individual burst of electrical current delivered to the grid array of electrodes, wherein the recording element is configured to detect any evoked potential responses that might be elicited from electrical activation of neural structures located in proximity to the particular combination of electrodes stimulated; the computer system further configured to mathematically analyze digitized information obtained from the recording element to detect and quantify any evoked potential responses associated with each particular stimulation configuration, wherein the computer system is configured to use evoked potential thresholding techniques to sequentially scan through multiple permutations of stimulation configurations and stimulation parameters to mathematically determine which stimulation configuration(s) yield lowest threshold evoked potential responses; and a video monitor or other audiovisual feedback device, wherein the computer system is configured to output to the video monitor or other audiovisual feedback device a virtual map generated by at least sequentially stimulating the varying combinations of electrodes utilizing at least the mono-polar, bi-polar, and tri-polar stimulation configurations and utilizing detected and quantified evoked potential responses associated with each particular stimulation configuration, so as to provide useful information that could alert a surgeon to the presence of nearby neural structures in proximity to the surgical instrument, provide the surgeon with information to assist in estimating a proximity of the neural structures in relation to the surgical instrument, and/or provide information describing a relative direction of a location of neural structures in relation to the grid array of electrodes, wherein at least two of the plurality of stimulation configurations define first and second mono-polar configurations that include at least a first one or more electrodes on the surface of the surgical instrument that are stimulated simultaneously when the first mono-polar configuration is utilized by the computer system, and at least a second one or more electrodes on the surface of the surgical instrument different from the at least a first one or more electrodes that are stimulated simultaneously when the second mono-polar configuration is utilized by the computer system, wherein at least one of the plurality of stimulation configurations defines a bi-polar configuration that includes at least a first two electrodes on the surface of the surgical instrument that are stimulated simultaneously when the bi-polar configuration is utilized by the computer system, wherein at least one of the plurality of stimulation configurations defines a first tri-polar configuration that includes at least a first three electrodes on the surface of the surgical instrument that are linearly arranged and stimulated simultaneously when the first tri-polar configuration is utilized by the computer system, and wherein at least one of the plurality of stimulation configurations defines a second tri-polar configuration that includes at least a second three electrodes on the surface of the surgical instrument that are not linearly arranged and stimulated simultaneously when the second tri-polar configuration is utilized by the computer system.