K.B.
I actually write a letter every year to my son on his birthday and put it away for the future. I tell him all the memories I have from the past year, explain the fun things we did and also go into his accomplishments of that particular year. It's a letter to him at that time but I'm saving them all together so to give him when he is older. I read this somewhere, and the father did it. He was saving them for his daughters 21st birthday. It sounded good, so I started when my son was born with his birth story. :)
I'm not sure if he'll appericate them as much as I do but I enjoy the time to reflect each year, see our strengths and helps me to realize where we need to work and improve. (Along with enjoying him more!)