Megan, at A Blossoming Homestead, wrote this article a couple of days ago. I particularly liked the story she mentions about Arthur Bremer. You'll have to go to her site and check it out.
I agree that there is something about wearing dresses and skirts that causes people to treat you differently. Actually, the biggest difference is that men tend treat you with more respect. I've had some, usually older women, say how nice it is to see women/girls all in dresses or skirts, but far and away, the most obvious difference is with men, young and old alike. I commented on her blog that I had a couple of young men, who were not watching their language despite the other women in the store, stop using bad language and apologize to me once they saw me in line for the cashier. We've had numerous such incidences over the last several years, so I know that there truly is power in wearing a skirt and comporting yourself in a ladylike manner.
We've only had a few negative encounters, and interestingly enough, they have all been with other women. One of these happened to the older girls a few years ago (they were about 15 and 17 at the time) when I sent them into the grocery store to grab a couple of items we needed. A woman made an unkind comment to the girls about wearing dresses and a man in line behind them stepped out and defended the girls before they could utter a word. According to the girls, he soundly rebuked the woman for her remark. They were still pretty flabbergasted when they got to the car. They said it was all they could do to remember to thank the man for his support.
And the best of all - my husband constantly thanks me for how the girls and I dress.