interesting: as one commenter (MH09, aka Michel Hannequart) already noted over there, in "français de France", foufoune / foufounette means vulve. I always assumed some vicinity with touffe (extremely short mini-skirts are vulgarly known as jupe à ras-la-touffe or ras-la-foufounette round here).
As for bizoune, people here say zigounette, hypothetically an hypochoristic of *zigoune, which, however, I have never read or heard anywhere.

(Given the popularity of my last comment on "sexual language", I probably shouldn't indulge into this, but this time I'm on topic, at least.)

I already knew about the France/Quebec 'foufoune' contrast - but this kind of slight meaning shift is not unusual. Of the top of my head, cf English 'fanny', which means 'bottom' in US English, and 'vulva' in many dialects of Northern England and Wales.

In a side note, coincidentally enough I was at a show last night at a well-known bar here in Montreal called 'Les Foufounes Electriques'

Well, 'Les Cowboys fringants' are in Paris, but that's not as amusing. I just remember another 'faux ami': gosse ('kid' in France, 'bollock' in Québec).

Letter to Kevin and Pauline, Bilingual Kiwi Kids in France, a mommy-blog, recently had a post about what French words to teach the kids.