1. A communication system for at least one of monitoring the performance of an implantable medical device (IMD) implanted within a body of a patient, monitoring the health of the patient and remotely delivering a therapy to the patient through the IMD, the IMD being capable of bi-directional communication with a communication module located external to the patient's body, the system comprising: (a) the IMD; (b) the communication module; (c) a mobile telephone operably connected to the communication module and capable of receiving information therefrom or relaying information thereto; (d) a remote computer system; (e) a communication system capable of bi-directional communication with the mobile phone and the remote computer system; and (f) means for generating an invoice when communication is one of initiated between the IMD and the remote computer system, the IMD and the communication module, the communication module and the remote computer system, and the communication module and the communication system.