Obviously, languages like Japanese, Chinese, Arabic - all very useful for certain sectors of the business world. But... I don't think many companies would want to send a woman to an Arab country for business dealings.
I am wanting to try my hand at another language next semester and am not sure what to consider besides Spanish. I'm considering Chinese, as we have a new program teaching it at my school - but I kind of had to pause and think about what my interaction with other cultures may be like and how different it would be as a woman.
Japanese is out because I don't want to be the girl with a penis in a classroom full of guys who beat off to hentai.