1. A method for automatically estimating the spatial positions between cameras in a camera network, the method comprising transmitting unique identifying signals between a plurality of spatially separated nearby cameras; wherein said identifying signals comprise identifying signals selected from the group consisting of electromagnetic identifying signals, RF identifying signals, infra-red identifying signals and ultrasonic identifying signals; measuring the received signal strength (RSS), time of arrival (TOA), or time difference of arrival (TDOA) of said identifying signals; and estimating the relative distances or positions between at least some cameras from said received signal strength (RSS), time of arrival (TOA), or time difference of arrival (TDOA) measurements to thereby determine the neighboring relationship among said at least some cameras.