Well, it's interesting that a lot of the photos posted here are drag queens and satire (i.e. Jake on SNL). Camp is a really important thing, so I'm definitely not dismissing it.
But, to me it's interesting to think about the question of men and dresses on a different level. Women fought for the right to wear pants for a long time. And, there are men who would like to be able to wear skirts/dresses without ridicule. It's about having the choice to wear a dress if you want to regardless of what sex you happen to be.
I remember there was a boy in my high school (not gay or bisexual as far as I know. He was more of a punk-hipster than anything else)... who really wanted to be able to wear skirts to school. He kind of waged his own campaign about it... wearing skirts to school quite frequently and also getting into a lot of trouble for it on occasion. The fact that he got into so much trouble (and he wasn't wearing anything immodest or revealing... usually knee length black skirts) really emphasized how unfair and stupid dress codes and gendered dress codes can be.
When Bowie wore his dress on the cover of
The Man Who Sold the World in 1971, that cover was censored in many places so that an alternative cover had to be produced for certain markets. One of the interesting things about Bowie's dress from the cover (and others like it) is that it was a "man's dress" designed specifically for a man's body. He's not technically in "drag". He did his first tour of the U.S. in his "men's" dresses like this.
But, it's interesting that the most androgynous moments are sometimes just head shots with the appropriate attitude.
When Placebo did their first shows in the U.S. Brian was very much in his dress-wearing mode. This is a YouTube of Bowie performing one of Placebo's songs with them in the late 1990s (and Brian is in a dress here). I think Bowie saw a lot of himself (and of Marc Bolan) in Placebo. Placebo opened for Bowie for two different tours in the 90s.
[youtube=425,350]http://www.youtube.com/watch?v=_GqnDROi6l4[/youtube]
And, when Brian Molko wears his dresses, he does occasionally use the word "drag", but he doesn't really mean it in a camp or "funny" way at all. It's really just about Brian being able to wear a dress if he wants to - and to look really good when he does so (and to challenge the sexual assumptions of people looking at him). When he wears pants (which is usually) it's important to note that he's still usually wearing women's pants... many of his shirts are women's shirts too. So wearing clothing designed for women isn't just about wearing dresses.
Brian's another one where his most androgynous moments don't always involve a dress.
(well the second one is a dress, but it's not evident in the cropping of the pic)
One of the songs from Placebo's first album is called "Lady of the Flowers" and is based on Jean Genet's 1943 book called
Our Lady of the Flowers. The Genet book is about gay subculture in Paris and features many male characters who go by female names and wear women's clothing. Here's a YouTube of an early performance of this song... one of the best rare Placebo YouTubes out there IMO - a great example of the mystery and atmospherics of early Placebo shows.
[youtube=425,350]http://www.youtube.com/watch?v=svT-W4bh0BQ&feature=related[/youtube]