<P>"My grandpa is my pen pal." Annie tells her class at show-and-tell one day. It's true. Annie and Grandpa have written each other letters since the day Annie was born. When Annie was a baby, her mother answered Grandpa's letters. When she got a little older, Annie told her mother what to write. But now that she is in school, Annie can read Grandpa's letters herself -- and answer them, too.</P>