I personally can see both sides of this argument and think that this issue is between a person and Christ. Please read, before discounting
As for the "animals" argument: I think its clear that human beings are different from animals. Very different. I never want to be compared to the beasts of the field, as Nebuchadnezzar and Nero (in history at least, and scripture if you see him as "666") both were. You're gonna need a better argument. We're made in God's image, dolphins, dogs, or any other animal that engages in this behavior is not.
As far as the "redefining scripture" argument goes: It seems to me, we're trying to do our best to interpret documents written almost 2000 years ago, to their cultures, and we need to be gracious to both sides of the arguments to get anywhere in this. I don't want to assume the worst of my adversary (or their intentions, as only God knows that) in any debate, as that quickly degenerates into ad hominem arguments. For this BOTH of us would need better arguments.
I personally can see how the passages dealing with homosexuality could be interpreted as dealing with the sexual sin inherently involved in idolatry (such as fertility cults). The question, in my mind is, "do the homosexual acts today, IF the practitioner is not practicing idolatry, still fall under the umbrella of the passages in question?"
Are there passages that one may find that the context of it does not seem to speak of Pagan idolatry, either as a warning to the Jews entering the lands of these people, or to new Gentile converts coming to Christ?
All this aside- the issue that remains is a hypothetical one. The Spirit will lead us to all righteousness, and His role is conviction- believer and the world. Homosexuals, IF Christ does indeed view your activities as sin, WOULD you stop it, or at least desire to stop it, your fellow Christians understanding the difficulties all of us face in besetting sin? I have personally found that when I am in a sin I wish to remain in, I will justify it to the point of dodging this issue, or simply retorting with "Yes, but it's not!"
If homosexuality is a sin, Christ bled just as much for it as He did for my sins. I for one will welcome anyone into my church, but they need to be warned that if the Spirit convicts them of sin in their life they are personally responsible for repenting. In short- we should welcome them into our church, but we cannot offer anyone any unconditional guarantee Christ will welcome them into His, as HE, not us, knows the heart.