Read Judith Butler

Luce Irigueray
Mary Daly
Audre Lorde
Susan Griffin
Germaine Greer
Vandana Shiva
Julia Kristeva
Carol Gilligan
and those are the ones that come to mind off the top of my head. I've never studied philosophy but I've been influenced by all of these.

i would add

bell hooks
pema
melanie klien
wendy doninger
marie louise van franz -- was a radical in her day. she withheld the publication of her wemons mysteries book on moon goddess traditions until after jung's death because he thought it was to radical. it went someplace he could not.....

and i wonder, how are we defining philosopher? like does that mean rubbing elbows with the big boys in the misogonistic halls of academia? like what if that male model that thrives on power, individualism, and the occasional knife in the back is not, is not, is not, the place where wemon tend to thrive, (some disciplines more or less so than others) and so we work elsewhere.... where our work has meaning-- in society/community perhaps. i dont know.

i will say, i went to hear a friend of mine give a visiting guest lecture at the u of wa philosophy dept a few months back and while the room was occupied by "mostly" males, there were some wemon there, at least one of the five faculty present, one of three visiting faculty, and a student or two. i was there, representing interested community members i suppose. so we are represented in the halls of the academy .... seven of twenty some maybe?

I was lucky enough to study with Mary Daly for a semester at Boston college...

Susan Sontag.

en.wikipedia.org/wiki/Susan_Sontag

Zsusanna Budapest
en.wikipedia.org/wiki/Z._Budapest

The creators of Bitch: A Feminist Response to Pop Culture have a lot of budding female philosophers working with them in ways ranging from serious to sardonic to sarcastic to grab-your-guts hilarious.
www.bitchmagazine.com/

And if you're still needing some names, go here for a few more:
www.heartless-bitches.com/cultu....shtml

Riot Grrrl is a kind of philosophy that was spearheaded by Kathleen Hanna & her band Bikini Kill and a group of young women living in Washington state. It eventually took off to other parts of the world, and though some of thier message has been distorted in the mass media, Hanna and most of the young women who started the original Riot Grrrl chapters are still making media their own way.

en.wikipedia.org/wiki/Riot_grrrl

how about kathy acker? she's kind of the punk of female philosophers, i'd say. she wrote "blood and guts in high school."