Also on these boards
Yearly photos w/ interests noted. Make up a few pages in photoshop or an editing program of choice, and create a printed 8x10 book. Give to your children when they graduate as a gift...I would use a few head shots and definitely lifestyle candid shots to get the real feel of what they were like at each age.
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!
Document what he wants to be each first day of school.