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.
Did it! Made one for an Activity Day girl who recently moved away. I had all the girls sign the balloon. They loved it, and the little girl loved it, and appreciated being remembered. Also, cute idea to send to grandmas from wee ones, or cousins for b-days.