Up and Down, written and illustrated by Oliver Jeffers, Philomel, $16.99, ages 4-8, 32 pages. A boy and a penguin return from the South Pole the best of friends and for a time do everything together until one day the penguin decides he has to do something by himself: fly. Though everyone knows penguins can't fly, the penguin does his best to make it happen. He even climbs onto a chair on top of the boy's dresser and plunges off. (Luckily the boy is waiting below with a pillow.) But nothing seems to work. The boy even offers to take the penguin for a ride in his plane, but the penguin is determined to do this alone. Still, the boy wants to help and together they head to the zoo for answers. But soon after arriving the penguin sees a want ad for a living cannonball and in his excitement, rushes off to apply without telling the boy where he's headed.