Joined for Life: Abby and Brittany Turn 16 is a documentary about Abby and Brittany Hensel, conjoined twins who are essentially one physical person with two heads (as well as a few other body parts). From a review of the film by Kevin Kelly: "Endless questions ensue from this documentary about their suburban life. If each girl controls only one arm and one leg, how can they ride a bike? Hit a baseball? Swim? When they drive a car, how do they decide where to turn? And do they get one licence or two? That particular question is answered on their 16th birthday, as this film follows them to the driving test center, where they pass the driving test (both turning the wheel). Their local DMV decides to issue them each one licence."
A clip from a previous film on the girls is available on YouTube.