Tough subject.
Maybe there are things we can do about this sort of prejudice. Even if part of it is biological (e.g. maybe we subconsciously prefer features that indicate better health or something?), there's clearly a lot which is cultural, and that part is changeable.
Also, I can't help but think that this post by NotPhil is completely relevant: http://hubski.com/pub?id=3098
I couldn't decide whether to support that article's ideas or not. Even admitting that I might discriminate (or be discriminated against) because of "ugliness", and the idea that it's an objective category that could be set in law... it's weird. But then, if we humans actually are biased in this way, and these attitudes do have a measurable effect in the world, then maybe a legal category would bring the problem out into the open and we'd have to at least acknowledge we're doing it.