When each of my children are born, I go out and get a journal for them. Not for THEM to write in, but for ME to write things about them.
Each month I write a note to them in this journal and tell of what new things they are doing and how much I love them.
I intend to do this till they leave our house and head out on their own. At that point, I will give each of them their journals so they can see who they were when they were little, what funny little things they said or did, and what they meant to me.
It has also been really nice for me to do this because on those days when I just want to run far.......FAR away, it reminds me why I don't want to miss any moment of this!!!