1. A method of operating an electronic device comprising the steps of: initiating entry of a content string; determining a most probable completion alternative using a personalized and learning database, wherein the personalized and learning database comprises recently used data, said data comprising any of: one or more word associations, one or more context associations, one or more sensitivity associations, one or more Uniform Resource Locators, and one or more electronic mail addresses, said determining comprising: storing the personalized and learning database in memory; storing content and sensitivity associations of entered content in an associations memory; storing one or more language dictionaries as chosen by a user in a main dictionaries memory; receiving, by the personalized and learning database, inputs from the associations memory, the main dictionaries memory, and a recent entries memory; using the inputs, re-sorting said recently used data in the personalized and learning database combined with content used by the user and consequently customizing re-ordering of content based on personalized usage; and using the re-ordered content stored in the personalized and learning database and using content stored in user interface memory to provide a customized depth of prediction in predicting the most probable completion alternative by allowing the user to control the depth of prediction by providing user input that indicates whether the entire prediction or one or more portions of the prediction are accepted and wherein depth of prediction indicates whether a predicted character, predicted word, or predicted words encompassed within a phrase all at once is accepted; displaying the most probable completion alternative; determining whether a user has accepted the most probable completion alternative; and adding the most probable completion alternative to the content string when the user has accepted the most probable completion alternative; providing a user interface that comprises a navigation key having a first set of controls and a second set of controls; wherein said first set of controls are configured for acceptance or non-acceptance of the most probable completion alternative currently displayed at the display when in an editing mode and said second set of controls are configured for changing or overriding the most probable completion alternative currently displayed at the display when in the editing mode; wherein said first set of controls are configured for scrolling a cursor right one character at a time or scrolling the cursor left one character at a time when said first set of controls are in a navigation mode; wherein said second set of controls are configured for scrolling the cursor down one line at a time or scrolling the cursor up one line at a time, when said second set of controls are in the navigation mode; and wherein: a right control of said first set of controls is configured for, in navigation mode and in a hold and press mode, jumping the cursor to the right one word at a time; a left control of said first set of controls is configured for, in navigation mode and in the hold and press mode, jumping the cursor left one word at a time; the left control being further configured for, in editing mode and in the hold and press mode, dismissing prediction and locking a last key press entry.