1. A method, comprising: at a multifunction device with a touch screen display: displaying content on the touch screen display at a first magnification, wherein the content includes selected content; detecting a finger contact on a respective end of the selected content; displaying a content magnifier adjacent to the respective end of the selected content, wherein the content magnifier displays: an expanded portion of the content proximate to the respective end of the selected content at a second magnification that is greater than the first magnification, and a boundary marker that denotes a current position of the respective end of the selected content; detecting movement of the finger contact across the touch screen display; updating the respective end of the selected content and the displayed expanded portion of the content proximate to the respective end at the second magnification in accordance with the movement of the finger contact; and moving the content magnifier and the boundary marker in accordance with the movement of the finger contact.