First, you need a Emergency Information Sheet. This sheet should have local police (emergency and non-emergency), fire, health dept, red cross, ambulance and local shelter numbers for starters. You also want to list on this sheet each family members - name, date of birth, blood type, allergies and any medications they are taking. This should be your central list, easily accessible for everyone in the house. I would suggest adding family and friends locally to call in case of an emergency as well as an out of state/town contact. Also, think about adding doctors names and numbers to the list.
Second, you need a list in each 72 hour kit with the above information as well as your families rally/meeting place. The "in case we get separated meet _____" place. You should have a local meeting place and an out of town/state meeting place. It may seem silly, but disaster can strike at anytime, day or night. Where are your loved ones right now?? I doubt everyone is right next you or even in the home. We go to work, school, shopping, etc. What if you block is evacuated, what if your drive home is no longer drivable? Where do we go? Who do we contact? If we plan in advance we will feel less panicked and will have greater peace.
"If ye are prepared ye shall not fear..."
Note: The importance of having an out of area contact is if the local lines are tied up/down, you are more likely to be able to reach someone outside of the area to let them know you are okay. Imagine that a large earthquake happens where you live or where someone else in your family lives and of course you can't get a hold of that person - wouldn't it be great to be able to call your (brother, uncle, grandma or whoever the contact is) and have them say that they have heard from them and everyone is alive, etc.
I have also had it suggested to me that keeping copies of important documents (drivers license, birth certificates, etc.) is helpful to have in your kit. As well as a family picture.
Sorry about all the "What ifs..." but if you think about this in your life, with a real application it is more likely to inspire you to action.
(If I can manage the time and can figure out how to post it here, I will make a Family Emergency Plan template and post it here, but don't wait for me to get started.)