Balloon twisters are another popular choice for young children’s birthday parties. Highly skilled entertainers, such as Circus Dynamics in Providence, Rhode Island, or Balloons by Zippy in Washington, D.C., can make an astonishing variety of shapes, including hats, animals, toys and other sculptural forms. They generally charge by the hour. For example, Chicago’s TwistiCity charges $120 an hour, including all the balloons and air pumps.