Well... The thing is that I'm not sure that this is a matter of gender stereotypes / sexism so much as it is a matter of 'if you want to be treated as a person then you need to present yourself as a person'.

If a guy really swaggered and played with his biceps and / or wore clothes that drew attention to masculine characteristics then I think that he would similarly find that people (on first impressions) didn't take what he had to say so seriously (the people who I associate with at any rate).

And that isn't to say that guys can't exhibit a sense of taste and / or personal style. (It is interesting to me that with human beings women have become the 'flashy' gender. In the majority of the rest of the animal world the males are flashy in order to court the females - consider the peacocks tail. How did that get to be reversed in human society (assuming that humans used to be like that too)? And how is that to the interests of the females (as opposed to the males)??.

I'm not sure how much it is about one needing to campaign to change gender stereotypes so much as it is about limitations on the attention capacity of human beings. When attention is limited (as it is) and people are tired (as they get) then where does their attention naturally wander? If you show cleavage then don't be terribly surprised if people stare at your boobs. Hell, I find myself staring at womens boobs - not because I'm into boobs, but because what they are wearing is designed to get your attention to wander. Why show your cleavage if you don't want people looking at it? But when people are attending to that don't be surprised that they aren't listening to what you are saying terribly well...