it is so nice to find other obsessive compulsive disney folks like myself. i no longer feel unusual.
i make a small calendar for myself with the schedule for each day and under each reservation i put the number. then i shrink it on the copier to credit card size and laminate it and stick it in my camera bag. have everything of import with me, small and convenient.
(btw- i also have a daily card for each daily schedule, i.e. get FP then go ride something else, then go use FP, then go to lunch)
i have never, repeat, never, shown up at a restaurant and had any question about my reservation, if you make it, it's there. now if your travel agent does it, i would ask for a hard paper copy from them as i have heard about mistakes THEY make. or you could go to disney's website, put the ressie number in under "find missing reservations" and see it in black and white for yourself
but disney has never screwed up anything on me. so do i really need those numbers?........