15. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device with a display, cause the device to: display at least a portion of an electronic document at a first magnification level on the display; detect a first input indicating a first insertion point in the document, wherein the first insertion point is proximate to a first portion of text in the document, the first portion of text having a first font size; in response to detecting the first input: select a second magnification level different from the first magnification level, wherein the second magnification level is selected so as to display the first portion of text at a target text display size; and display a portion of the document at the second magnification level; while displaying the portion of the document at the second magnification level, detect a second input indicating a second insertion point in the document, wherein the second insertion point is proximate to a second portion of text in the document, the second portion of text having a second font size different from the first font size; and in response to detecting the second input: select a third magnification level different from the second magnification level, wherein the third magnification level is selected so as to display the second portion of text at the target text display size; and display a portion of the document at the third magnification level.
15. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device with a display, cause the device to: display at least a portion of an electronic document at a first magnification level on the display; detect a first input indicating a first insertion point in the document, wherein the first insertion point is proximate to a first portion of text in the document, the first portion of text having a first font size; in response to detecting the first input: select a second magnification level different from the first magnification level, wherein the second magnification level is selected so as to display the first portion of text at a target text display size; and display a portion of the document at the second magnification level; while displaying the portion of the document at the second magnification level, detect a second input indicating a second insertion point in the document, wherein the second insertion point is proximate to a second portion of text in the document, the second portion of text having a second font size different from the first font size; and in response to detecting the second input: select a third magnification level different from the second magnification level, wherein the third magnification level is selected so as to display the second portion of text at the target text display size; and display a portion of the document at the third magnification level. 18. The computer readable storage medium of claim 15 , wherein the electronic device includes a touch-sensitive surface, and the first input and the second input are detected on the touch-sensitive surface.