A clip from Charlie Chaplin's 1928 film "The Circus" is causing a stir as a woman in the background appears to be talking on a cell phone.
■Class discussion: The video poses some tough questions -- do you have the answers? How would the cell phone be powered? How could it work without cell towers? And, especially, who would she be talking to? If you went back in time, what would be more important to you -- your cell phone, your ipad, your ipod, your laptop?