5. The device of claim 1 , including instructions for, while continuing to detect the first contact and the second contact on the touch-sensitive surface: detecting that a gesture metric based on the first gesture is above a respective fading threshold, and in response to detecting that the gesture metric based on the first gesture is above the respective fading threshold, ceasing to display snippets of text other than the first snippet of text; and detecting that the gesture metric based on the first gesture is below a redisplay threshold, and in response to detecting that the gesture metric based on the first gesture is below the redisplay threshold, redisplaying snippets of text other than the first snippet of text.
5. The device of claim 1 , including instructions for, while continuing to detect the first contact and the second contact on the touch-sensitive surface: detecting that a gesture metric based on the first gesture is above a respective fading threshold, and in response to detecting that the gesture metric based on the first gesture is above the respective fading threshold, ceasing to display snippets of text other than the first snippet of text; and detecting that the gesture metric based on the first gesture is below a redisplay threshold, and in response to detecting that the gesture metric based on the first gesture is below the redisplay threshold, redisplaying snippets of text other than the first snippet of text. 6. The device of claim 5 , wherein a value of the redisplay threshold is related to a value of the fading threshold.