1. A system for remote, real-time ordering on a user telephone terminal items of merchandise or services from a provider of such items via a central telephone terminal, comprising: bar code reader means at the user terminal for machine reading bar codes selectively scanned by the user from a pre-provided catalog containing bar codes corresponding to such items and bar codes corresponding to a predetermined plurality of commands for controlling the central terminal; transmitting means at the user terminal for successively transmitting to the central terminal item orders and commands corresponding to selected bar codes scanned by the user while the user terminal is on-line with the central terminal, said transmitting means directly, in real time, converting signals resulting from the machine reading of the selected bar codes to DTMF signals and transmitting the DTMF signals to the central terminal over a telephone line; and receiving and processing means at the central terminal for receiving and processing item orders and commands successively transmitted by the transmitting means, each in accordance with the user's freely discretionary selections made while the user terminal is on-line with the central terminal, among the items and said predetermined plurality of commands from the catalog, said receiving and processing means automatically recognizing whether each transmission is an item order or a command and, when an item order is recognized, automatically storing the same, generating a corresponding confirmatory voice response describing the ordered item and sending the voice response over the telephone line back to the user terminal, and, when a command is recognized, automatically executing the command.