A method of using a mobile device to print onto a print medium, the mobile device comprising: a wireless transceiver for sending and receiving data via a telecommunications network; and a printer; the method comprising the steps of: (a) determining a geographical location of the mobile device; (b) determining a product or service available at, in or within a predetermined distance of, the geographical location; (c) formatting a voucher containing information associated with the product or service; and (d) printing the voucher using the printer.