J.K.
My son was absolutely BEAUTIFUL as a young child. He was born with long hair, killer long eye lashes (i still wish mine would look like that) and gorgeous features. As a baby dressed in all blue I still got oh SHE is so pretty! As a young boy he got that too some even after having a short little boy hair cut. Now at 10 the "popular" thing to do among his friends is to have long hair again. One of his friends has the most beautiful long, blonde hair... from the back many people think he is a girl. My advise is let your son be... if he likes long hair, leave it long until he wants it cut. When someone makes a commit about your cute little girl (either just say thanks and totally ignore them) or politely tell them thank you, you know your SON is adorable. Eventually your son will start speaking up too and tell them "I'm a boy!" so you don't have much longer to worry about it. And as M R. said there are many girls who LOVE to wear spiderman and other "boy" character clothes. ;)