Never heard of one of these...well, that I remember.
At the rate my brain cells have been jumping ship I suppose I could have watched a half an hour program on how to make one of these yesterday and forgotten it by today!
I have just 5 kids, and I usually have a rough estimate of weight and height, but the ol' memory thing isn't so good, so a notebook would be really helpful. I'm always having to dig out the SS #'s or birth certs for something or other, so having a notebook would be great!
Also for evacuation preparedness...I have a couple of Rubbermaid boxes with important stuff (papers) that we grab when we've had to evacuate, but having the more often used legal papers in a notebook would make them handy to grab in emergencies, and yet still handy for daily use.