From Real Simple: If you send money to nieces and nephews for birthdays, switch up the normal card with this clever idea. Put single bills or coins into balloons and inflate them slightly then fill a shipping box with the balloons and send it off. It will be inexpensive to ship, and plenty of fun to open.
Party in an envelope. Send to kids who couldnt make it to the Birthday bash. Personalized Balloon Bouquet - Mail empty balloons to friends family of Birthday person, they will each write a special msg on their balloon then send them to the Birthday Person (or for any special occasion or just a pickmeup)! How special would that feel to receive?!