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 and a touch-sensitive surface, cause the device to: concurrently display on the display a first text entry area, and an integrated input area, the integrated input area including: a left portion with a left side of a split keyboard with a first set of characters; a right portion with a right side of the split keyboard with a second set of characters; and a center portion in between the left portion and the right portion; detect a first input on the touch-sensitive surface; in response to detecting the first input, enter a reconfiguration mode for the integrated input area; and, while in the reconfiguration mode for the integrated input area: detect a second input by a first thumb and/or a second thumb; in response to detecting the second input, adjust the size of at least one of the left side and the right side of the split keyboard in the integrated input area, maintain the first set of characters in the left side of the split keyboard, and maintain the second set of characters in the right side of the split keyboard; detect a third input; and, in response to detecting the third input, exit the reconfiguration mode for the integrated input area.
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 and a touch-sensitive surface, cause the device to: concurrently display on the display a first text entry area, and an integrated input area, the integrated input area including: a left portion with a left side of a split keyboard with a first set of characters; a right portion with a right side of the split keyboard with a second set of characters; and a center portion in between the left portion and the right portion; detect a first input on the touch-sensitive surface; in response to detecting the first input, enter a reconfiguration mode for the integrated input area; and, while in the reconfiguration mode for the integrated input area: detect a second input by a first thumb and/or a second thumb; in response to detecting the second input, adjust the size of at least one of the left side and the right side of the split keyboard in the integrated input area, maintain the first set of characters in the left side of the split keyboard, and maintain the second set of characters in the right side of the split keyboard; detect a third input; and, in response to detecting the third input, exit the reconfiguration mode for the integrated input area. 17. The computer readable storage medium of claim 15 , wherein the third input includes the first thumb and/or the second thumb.