We should also replace a digit on the left hand with the penis. Thrusting the groin gets so tiring. And you wouldn't even need to take your pants off! Am I masturbating or just trying to keep my hands warm in this cold November weather? Who knows!
As a plus, this will cause left handedness to be phased out by 3030, as no one will want to shake hands with a lefty, thereby preventing them from passing a job interview without much awkwardness.