Hi Stan,
I don't believe any of the free services support this feature, but I do see a google labs feature that will get you most of the way there. Login to your Gmail account, go to settings, and the click the labs tab. Near the bottom of the list you can activate a calendar in your Gmail account. Enter the important birthdays in there and you will have a notification in your email account when it's time to send your contacts a happy birthday message.
-Raymond