Ask the same 20 questions year after year but probably age 3 or 4 is a great age to start) and see how your child's responses change year to year. Makes a great keepsake to give to them when they turn 18
Give the book to child's teacher at the end of each school yr and ask them to write a small note and sign it. Give the completed book to child at high school graduation. I received this book for graduation. I love having the teachers sign it though!
For those of you who have kids starting kindergarten next year. Starting in Kindergarten, put the child's graduation year on a large tshirt. Take a picture each year with same shirt to watch the child grow into the shirt. Display at graduation party!