From the time I had my first baby, I have always had an afternoon nap time at my house. When my first was a tiny infant, I would turn off the ringer on the phone around 1:00 so we wouldn't be disturbed and we would take a nap together.
As my children have gotten older, they don't always need a nap, but we still have a one hour period every day when everyone goes to lie down and rest. They can read books or listen to music or books on tape, but everyone must remain in their beds and be silent for the entire hour.
The little ones usually fall asleep and the older ones get some quiet time all to themselves, which is a rare commodity in a large family.
Mommy gets to catch up on phone calls, bill paying, sewing, blogging, or even a nap if I need one, too.
Once or twice, my oldest two have asked if they aren't too old for naps. I explained that they aren't required to nap, but we all need some time each day for a little peace and quiet, a time to think our own thoughts without someone or something else competing for our attention.
As far as I am concerned, no one is too old to spend an hour of quiet time each day. This is a must in our house and we all come out of our rooms a little more refreshed than we went in.