You know cats. They like to live by their own rules, ignoring the rest of the world as they preen, nap or stare out a window with not a care for you, their doting owner. But in this new spot for European mobile provider O2, directed by Caviar's Keith Schofield, one prissy puss undergoes a dramatic personality change, so much so you might want to call him Rover. Why? Because, as O2 believes, it wouldn't hurt the world to become a little "more dog."