redwelly 
Glad you liked my posts! I agree that the genderless aspect of Dr can be a huge boost to women working in male-dominated sectors. And I second Cally's sentiment that having visible role models is vital to inspiring young folk, especially girls, and to show that academia is open to anyone, regardless of their background.
Which brings me on to Goal's comment about "people thinking they are being terribly clever by not letting on what their gender is". I don't mean to be rude, but I think you are missing the point. Women who use Dr as a gender-neutral title aren't hugging themselves because they think hiding their gender is clever. They do so because gender stereotyping is still shockingly prevalent in our society, even in supposedly right-on sectors such as academia.
Take this study, where academics of both sexes were asked to rate the capabilities of a job applicant for a lab manager post, based on reading a CV. The CVs they were given were absolutely identical, save one details: half the CVs detailed a female name, half a male one. The academics (even the women) routinely rated the "male" applicant as being more competent, more employable and would offer him a higher starting salary than the "female" applicant.
These were academics who honestly didn't believe they had any gender-based biases. But they were biased, because years of cultural stereotyping about women being less competent/ worse at science than men had subconsciously affected their decision-making.
THIS is why women should not be shy about calling themselves 'Dr": because it will build a critical mass of academic visibility that will one day make all of this gender crap history.