Ben Maughan over at Pragmatic Emacs points to a useful package that lets you move back and forwards through editing changes. It’s implemented in the Goto Chg package. The easiest way of thinking about it is that it behaves like undo/redo without actually making any changes. It merely goes to the place where the change would be made.
That may not seem to useful at first blush but, in fact, I often find myself wanting to do just that. Sometimes it’s just that the buffer is dirty but I don’t remember making a change and this package makes it easy to see what that last change is. Of course, undo followed by redo does the same thing but it doesn’t allow you to easily scroll back and forth among all the changes.
The goto-chg package is available on Melpa and Marmalade.