A literal vagina dentata.
I squirmed all the way through the trailer, and haven't found much other information on the film other than a short review on IMDB describing it as a "gore-comedy" and claiming "If you appreciate cult, camp, or horror with a feminist edge, this is for you!"
Note the lead character's surname. O'Keefe. Hehe.
Until I see this (if I can bring myself to see it, so creepy! Oh yeah: release date is May '08), I'm not really sure what else I can say. Too little to go on. (Though: I bet that OB/GYN scene wouldn't have been the same if it was a female doctor she was seeing-- can only work w/ a dude.)
On a semi-related note, check out Rapex, an anti-rape female condom moving into production
in South Africa. How does it work? Well, it's like a tampon. Insert it in the vagina, and the plastic hollow tube has detachable barbs that lash onto any offending objects entering. The creator, Sonette Ehlers, calls it a "medieval device for a medieval deed." Yikes.