1. A method of operating a wireless handheld device, comprising: upon receipt of a request to use a messaging service, displaying a first recipient field for entering a recipient; upon detecting one keystroke of a key to which a first plurality of characters is assigned, displaying in the first recipient field one of the first plurality of characters; upon detecting one keystroke of another key to which a second plurality of characters is assigned, displaying in the fin recipient field one of the second plurality of characters: looking up address book entries from an address book that match either of: the combination of two characters displayed in the first recipient field; or any other combination of one of the first plurality of characters followed by one of the second plurality of characters; and displaying a selection menu of the matching entries; and upon receipt of an input corresponding to a selection of one of the matching entries: populating the first recipient field based on the selected one of the matching entries; ceasing to display the selection menu on the display; and altering the display to add a second recipient field for entering a second recipient address to the display so that the second recipient field is displayed below the first recipient field.