An individual signal unit; each said individual signal unit including; (a) a transceiver module, (b) a power supply, (c) a logic circuit, (d)at least one of a number of external event sensors, and wherein a signal from a said individual signal unit to a central control facility causes said central control facility to execute one or more predefined steps; at least some of said predefined steps configured or reconfigurable by an owner of said individual signal unit; at least some of the predefined steps provided by one or more independent parties; at least some predetermined steps configured or reconfigurable by said independent parties. Also provided is a monitoring system including an individual signal unit; said individual signal unit communicating with a central control facility when an event sensor activates said individual signal unit; said central control facility executing a number of predefined steps on receipt of a communication from said individual signal unit; at least some of said predefined steps configured or reconfigurable by an owner of said individual signal unit; at least some of the predefined steps provided by one or more independent parties; at least some predetermined steps configured or reconfigurable by said independent parties.