1. A method of monitoring the amount of time spent in a specified area by an individual, the method comprising: receiving a plurality of entrance images from one or more cameras, each entrance image containing a face of an entering individual who passed a first location; timestamping each entrance image with an entrance time corresponding to when the entering individual passed the first location and storing each entrance image in a database along with the corresponding entrance time; receiving an exit image containing a face of an exiting individual who passed a second location; timestamping the exit image with an exit time corresponding to when the exiting individual passed the second location and storing the exit image in the database along with the corresponding exit time; identifying a matching entrance image containing the same face as the exit image by at least comparing the exit image stored in the database to the entrance images stored in the database; and calculating a stay time for the exiting individual by at least determining the difference between the entrance time stored in the database corresponding to the matching entrance image and the exit time stored in the database corresponding to the exit image.