On the computer, when you make a mistake, there is a command “undo”(Undo) so that he goes back on the last thing done. But in the iPhone system, that there is no “Control-Z“, how to do? Not everyone knows, but since iOS 3.0 it is possible to undo the last thing you did on the device.
If you accidentally typed or deleted text, or regretted pasting a picture or word somewhere, just shake the device so that a small window Undo show up. Try it for yourself by typing and deleting text in the Notes or Mail application. The feature works on several others. ?