This is a modified demo of the YUI Drag ‘n’ Drop Sortable List demo. Changes made to the list can be undone using the history list module in the side bar. Try it by dragging the ‘Hamster’ item to the bottom, one item at a time. The history list will update and show a list of your actions. Click on one to go back to that point in history. See my post about ActsAsUndoable