Netflix offers an undo function in their Queue that allows users to undo a remove action. Users click an X icon to remove a movie from their queue, and the row is grayed out, showing an undo text link replacing the remove icon. The row persists until the user moves to a different page, so several removed rows may be visible if the user does repeated removes in one session. Upon return visits to the queue, the removed movies will be gone.
Prior to adding this function, clicking the remove control would simply remove the list from your queue, so if the user made a mistake, they would have to navigate back to the removed movie to add it back. The undo allows users to recover from mis-clicks or if they change their mind about watching that movie they just axed.