1. A computer-implemented method, comprising: at a portable electronic device, in a first area of the touch screen display, displaying a current character string being input by a user with the keyboard; in a space bar key on the keyboard, displaying a suggested replacement character string; replacing the current character string in the first area with the suggested replacement character string if the user performs a predefined gesture with respect to the space bar key on the keyboard; and keeping the current character string in the first area if the user performs a second predefined gesture with respect to the touch screen display.