Calling on ellyrae and Doug!!! these 2 are gems when it comes to things to say/put on cakes!!
http://www.craftsayings.com/archives/page7/overhillsayings.shtml
some cute stuff here....
Here's one from Ronald Reagan; hope I remember it correctly:
You know you're getting old when you're faced with two temptations and you choose the one that will get you home by 9pm.
Others:
It's no longer a question of staying healthy; its a question of finding a sickness you like.
Old age is no place for sissies.
By the time we've made it, we've had it.
Don't worry about senility. When it hits you, you won't know it.
Old age isn't so bad when you consider the alternative.
There are three periods in life: youth, middlge age, and "how well you look."
Gray hair is God's graffiti.
Growing old's like being increasingly penalized for a crime you haven't committed.
Old age is like a plane flying through a storm. Once you're aboard there's nothing you can do.
The three immutable facts: You own stuff. You will die. Someone will get that stuff.
The young man knows the rules, but the old man knows the exceptions.
Sex after 65 is like trying to shoot pool with a rope.
You're only young once, but you can be immature all your life.
Do not worry about avoiding temptation. As you grow older, it will avoid you.
(These were taken from the book Old Age Is Always 15 Years Older Than I am.)
Here are a few:
Age is an issue of mind over matter. If you don't mind, it doesn't matter. (Mark Twain)
There is still no cure for the common birthday. (John Glenn)
Old age ain't no place for sissies. (Bette Davis)
Don't let aging get you down. It's too hard to get back up. (John Wagner)
Inside every older person is a younger person wondering what happened. (Jennifer Yane)
I wish I could take credit for these, but they are from a website. For more go to: http://www.quotegarden.com/age.html
HTH!
glenda 
How about "Have a bury happy birthday" Too morbid??
Age isn't important...unless you're CHEESE!
great link to sayings for almost any occasion:http://www.scrapbook.com/quotes.php
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