1. A biometric sensor system configured to measure at least one physiological parameter, comprising: a first device comprising a generally flat Floormat configured to rest stably on a generally flat surface and to support the weight of a user standing thereon, the Floormat including: a weight-measuring system comprising at least one load cell and an amplifier system configured to measure a time-dependent load-cell voltage from at least one load cell and to process the time-dependent load-cell voltage to determine a current time-dependent load-cell waveform; and a first electrode disposed at an upper surface of the Floormat and in position to make contact with the sole of one of the user's feet when the user stands on the Floormat; and a second device comprising a Handheld Sensor configured to be supported at a region of one of the user's hands, the Handheld Sensor: 1) including a second electrode disposed in position to make contact with skin in the region of the user's hand when the Handheld Sensor is supported thereat; and 2) being electrically connected to the Floormat via a cable having one or more electrical conductors disposed therein; an analog system configured to receive biometric signals from the first electrode and from the second electrode and to process the biometric signals to generate a current ECG waveform, the analog system being located in one of the first and second devices and the electrode disposed in the other device being electrically connected to the analog system by means of said one or more electrical conductors; and a processing system configured to receive the current time-dependent load-cell waveform from the Floormat and the current ECG waveform from the analog system and to process the current load-cell waveform and the current ECG waveform, wherein the processing system comprises: 1) a computer memory configured to store therein historical ECG waveform data corresponding to a plurality of users who have stood on the Floormat; and 2) computer code configured to first identify a pool of potential users that could be standing on the Floormat based on a current weight value and then to compare the current ECG waveform against the historical ECG waveform data for the pool of potential users to identify a given user standing on the Floormat.