1. A method performed by an information appliance, the method comprising: receiving a first text input from a user and displaying the received first text in a user interface of the information appliance, wherein the information appliance is operable to invoke a plurality of commands in response to receiving command input from the user, and wherein receiving the first text input is not associated with any of the plurality of commands; receiving a second text input from the user and displaying the received second text in the user interface, wherein receiving the second text input is not associated with any of the plurality of commands; receiving a user input selecting a portion of the displayed first text; after receiving the user input selecting the portion of the displayed first text, receiving a command input from the user that designates the displayed second text input as being command text; after receiving the command input, selecting a first command from the plurality of commands according to the command text; and invoking the first command, wherein the first command uses the selected portion of the displayed first text as an operand.