1. A portable electronic device, comprising: a touch screen display; one or more processors; memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for: displaying at least a portion of a web page on the touch screen display, wherein the web page comprises a plurality of boxes of content; detecting a first gesture at a location on the displayed portion of the web page; determining a first box in the plurality of boxes at the location of the first gesture; enlarging and translating the web page so that the first box is substantially centered on the touch screen display; while the first box is enlarged, detecting a second gesture on a second box other than the first box; and, in response to detecting the second gesture, translating the web page so that the second box is substantially centered on the touch screen display.