Did you see this fascinating story in NYT about the sworn virgins of Albania? These aren't young women who swear not to have sex till marriage. Rather, they are part of a centuries-old tradition in which women decide to forgo sex and marriage in order to live as men for their entire lives. In the past, it often happened when the male head of the family died and there was no male heir to take his place. An older daughter would step up and become the patriarch, dressing like a man, doing a man's work and being treated by everyone as a man. It was also a way to gain independence and a sense of self worth in a time and place where women were considered no more valuable than a farm animal and many were forced into arranged marriages. I have to say it sounds like more fun that becoming a nun, which was the only way to avoid marriage in some Christian countries in days of yore.
Interestingly, once they became sworn virgins, these women were treated respectfully and accepted by men, even though they usually kept their female names. They were even allowed to own property, a privilege denied other women.
The custom is dying out now that women have more rights, and one sworn virgin in the article is quoted as saying she wouldn't do it today because she thinks now it would be fun to be a woman. I have read about the "two spirits" of Mexico, where a person of mixed gender identity was treated with respect and even awe. Anybody else know of any other customs around the world in which changing gender is part of a tradition?