John August's latest post offers a nice extension of the discussion of female characters I brought up in my last post. (Basically, a vast majority of films cannot pass a simple test: 1. the film has two or more female characters with names, 2. the characters talk to each other and 3. they talk to each other about something other than men.)
It's not a perfect test, but John himself admitted that he didn't used to think about these things before, and that he will now. Like I said, it's a choice: It's up to us, as writers, to choose how we portray women (and to portray them at all).
I think it's also worth mentioning that TV shows fare much better than movies when it comes to this test.