My youngest is 3 and, as long as it's humid, he has angelic, soft ringlets from about the top of his ears, down. I just can't stand to cut it! This past winter, when the humidity tapered off and his hair was straighter, it was pretty long. I told my husband when it warmed up and I could get one more REALLY good photo of his curls, I'd be ready to let him get his first haircut. But, of course, when it got warmer and the ringlets came back...I can't cut it!
To make matters worse (I guess), he has a very pretty face and beautiful eyes. So, even in his "I get my handsome from my Daddy" T-shirt (or wearing blue trucks...) people tell me what a beautiful daughter I have. Really? Who cares? He'll only be little once! And anyone who knows him knows he is all boy and nothing, if not confident. I just don't see him getting insecure, if he realizes people think he's a girl. He's more likely to call them an idiot (the influence of 3 older brothers) than to have hurt feelings.
My friend has two boys, just a couple years apart. The younger one is just...cool. Even at 3, he seemed cool. His older brother has a traditional haircut, but the younger one likes his hair long. His Mom lets him have his way - and he just looks great!
More extreme: there's a kid at our church whose gender my husband and I just can't figure out. He/she is maybe 10-12 and has waist-length hair, kind of wild and wavy, like boys with long hair (instead of sleek and perfectly-groomed like some long-haired girls). He/she never wears anything you wouldn't see on a boy. But he/she has a really pretty face. So...either a very cute and also very sporty girl, or a really good-looking boy who's comfortable enough with himself to wear long hair. Win-win! You just can't find it offensive, either way!