The week before last I spent on two university campuses, separated by a pretty far distance on any spectrum you'd care to name. On both, I was walking through campus with a (different) friend when we saw signs saying "LGBTQ." In both cases, my friend, no stranger to campuses in either case, stopped to wonder what "Q" added to "LGBT."
The answer turns out to be that, while Gays think of themselves as men and Lesbians think of themselves as women, Queers -- in the words of the surprisingly good Wikipedia entry -- deny that gender [sic] is part of the essential self. That is, Queers theory holds that no fact about gender is not socially constructed.
Now, much of sexual identity is socially constructed. Little Victorian boys in both Britain and upper class America ran around in long hair and dresses, which in no way prevented them from conquering the world. Gay men claim that a cornucopia of anonymous sex is the true expression of male sexuality, but I beg to differ. Much of who we are as men and women depends on what society expects us to be.
But that doesn't mean that Queer Theory isn't fundamentally nuts. First, there are differences between men and women beyond the purely biological. For example, while different cultures have different rates of violence, the ratio of violent acts committed by men to those committed by women is surprisingly stable across cultures. Across cultures, young men die at disproportionately high rates when compared to young women -- men take risks that women don't take.
Second, like the academic feminism that birthed it, Queer Theory consigns itself to impotence. Society is so warped by the patriarchy that all that can profitably be done about it is peer reviewed whinging for tenure. We are where we are; we can't go back. Make the best of it.
Third, notice how these peerless thinkers have divorced themselves from mainstream Western history, philosophy, thought and science. They misread Foucault and Derrida by thinking that anything can be treated as text, from our genetic code to what we non-Queer Theorists laughably refer to as the facts on the ground. What more anti-Darwinist idea can there be then that we are really self-defined selves free from constraint? At the same time, what more anti-religious idea can there be?