Well, I find nothing wrong with homosexuality, or the less extreme bisexuality. Now, the chicks at school who are
bi just because everyone is doing it are dumb (same with gay people with the same reasoning) but if you truely feel that way, more power to ya. Personally, I can't see why anyone would like men, we're flappy and lopsided, but I'm glad someone does.
As for Nature vs. Nurture, I still think this is split about 50/50, you can be born with weird hormones that make you choose the "unnatural" sexuality, but it could also be learned and picked up through your experiances (maybe you're straight, and in a relationship that ends badly, so you choose to move to the other side for a while and find you like it).
People should be allowed to do whatever they want, as long as it doesn't interfere with others. I don't want to see a gay parade, because parades block traffic, but I also don't want to see a ban on gay marrige, because that's a violation of rights.
Just have fun with your life, no matter how you choose the live it (unless it gets in my life's way, then stfu.)