Do something nice for yourself this year! Ask them if they can watch your offspring tomorrow as another part of your birthday gift, then take the day to lounge around, do some arting, watch trashy TV, read a great book, do your nails, take a two-hour bath with a glass of wine, spend the day on Ernya telling everyone it's your birthday so you get free gifts... anything you can imagine doing that you don't get to do because you're an adult with responsibilities. The possibilities are limitless.
You could clean out your closet and then drag your favourite blanket in there with you and take a nap...
Dress up like a rockstar with huge hair and sunglasses and go walk around your grocery store and see if anyone whispers....
Set up a blog and Twitter account and set a goal to have at least three followers by sundown...
Gather up all the scrap paper in your house, rip it in to small pieces, paint them each a different colour, and make a collage for the baby's room...
Search your couch for spare change, deposit it into your bank account (they'll look at you funny; do it anyway) and use Paypal to convert it into hearts...
Use the day to train yoursef to write or draw with your other hand...
Anything you can think of. Give yourself the gift of an entire day to be fun and spontanteous and NOT productive. Forget all about the world.