Harry Potter and the Prisoner of Azkaban - It Really Is Magic
In the third Harry Potter movie when Harry, Ron, and Hermoine are going to see Hagrid before Buckbeak is put to death, they run into Drako. Hermoine puts her wand to Drako's throat to hurt him(shes holding the wand with her right hand), then all of a sudden she punches him with her right hand and her wand has jumped to her left. I knew wands were magical but I didn't know they could do that!
This is easily explained. When Hermione pulled the wand away from Draco's throat, the camera never goes below Hermione's waist. So, she, having read her script, switched the wand from the right to the left hand so that she could punch Draco with her right hand.
Actually that person is right i've got it on dvd (got family in usa) and you don't actually see her change wand hands, she doesn't lower her hand until seconds before she gave Malfoy what he payed for.