Pleo is a one week-old dinosaur and he is the newest robotic marvel. Pleo has a sophisticated sensory system that has devices that enable him to see, to sense touch, and to detect objects. Stroke Pleo from head to tail, and he'll blissfully arch his back. But if leave a sociable Pleo alone too long, Pleo may become sad. How can you tell? That pleading call and forlorn look let you know that he's looking for a friendly pat or another chance to grab his favorite toy.