In case any reader is thinking of turning red, and trying to seem like a redhead to get all the added benefits (see above), here are a few pluses and minuses to consider first:
You can never be invisible. You want to avoid your landlord, or your ex? Forget it.

People always stare at you like you're a creature with three eyes. They also look at your hair, rather than into your eyes.
You get to be difficult, moody, silly, sullen. You're allowed to be yourself in all your moods and there's no guilt. This is definitely a plus.

When you get pissed off, your boyfriend doesn't ask you if it's your period. He just thinks it's your hair.
If you can't spell, well, you'll get the job anyway. Bank presidents like to have redheads at their sides.
Old men with Rita Hayworth still on the brain will smack their lips at you.

You provoke randy behavior-- even from dogs.
You don't have to join clubs or play board games at parties.

You can be a loner and stare at the fire if you like (my biggest plus).
If you're an actress, you'll probably get a role tailored specifically for you to highlight your crotch (see Altman's Short Cuts).
Nicknames are spawned monthly for you by your friends, your lover(s), your mailman. Insecure women won't like you, because red hair is like a red cape in a bullfight arena. It makes male hormones surge. Minus? No, plus. Who needs insecure friends?
If you happen to have been born a blonde or a brunette, you can pretend to be a redhead, but you'll always be shown up. You've simply had it too easy.