I'm not some eloquent activist speaker, so I'm just going to express my views here, and to hell with whether or not they represent any "mainstream" ideas. To me the "homosexual agenda" is simply the desire for straights to leave us the hell alone to live our lives as we were made, without trying to punish us, reprogram us, condemn us, murder us, or in any other way treat us as subhuman creatures.
Sometimes I wonder if I have any right to speak out at all, since I'm bisexual. Then I think of the German Jews who had "Christian" names in the 1920s and 1930s. The way I see it, as a bisexual, I'm in the same boat as those Jews: I can pass as a straight, but as soon as my cover is blown, I'm subject to the same oppression as the most blatant drag queen. I owe it to those around me - and to my own sense of integrity - to stand up for what's right, especially since I could slip through society without being noticed.
The links I've found most useful are: