Ringling Bros and Barnum and Bailey continuous offers free tickets to your baby for their first visit to the circus if you sign up for one before your child turns 1!
Here's what you need to do: head over to this link, sign up, wait for them to send you an email and then they will mail you a voucher (for lack of a better word) for a free ticket to the circus.
Don't worry you don't have to take your newborn to the circus now - the certificate has no expiration date! When you want to redeem the voucher you have to take it to a box office (the key is going to be to put these someplace you can find them easily when you are looking for them).
You can only register one child per year (although in the faq section it does say they make exceptions for twins).
I did this for MGirl when she was a baby and now I just did CMan. Will make for a nice (cheap) family outing some day.