Smile.

She smiled at a sorrowful stranger. The smile seemed to make him feel better. He remembered past kindnesses of a friend and wrote him a thank you letter. The friend was so pleased with the letter that he left a large tip after lunch. The waitress, surprised by the size of the tip bet the whole thing on a hunch. The next day she picked up her winnings and gave part to a man on the street. The man on the street was greatful; for two days he'd had nothing to eat. After he finnished his dinner, he left for his small dingy room. ( He didn't know at that moment that he might be facing his doom.) On the way he picked up a shivering puppy and took him home to get warm. The puppy was very greatful to be out of the storm. That night, the house caught on fire. The puppy barked the alarm. He barked until he woke up the whole household and saved everyone from harm. One of the boys that he rescued grew up to be President. All this because of a simple smile that hadn't cost a cent.