Some of my recent posts and comments may have been polemical without being clear. I've allowed some confusion to develop between the issues of same-sex civil marriage and Jewish commitment ceremonies. I happen to be in favor of both, but they are distinct issues and it is of the utmost importance that they remain distinct.
Fleurdelis28 points out that civil marriage has already undergone tremendous changes. In most states, the law simply registers partnerships and leaves all major decisions regarding those partnerships in the hands of individual couples. Couples can dissolve their marriages at will; the law requires no justification. Adultery is no longer illegal due to a growing sense that it is not the government's place to legislate morality.
To my mind, it should be easy for members of religious communities to accept this policy of individual discretion, since we have other institutions to tell us how a marriage should work. I see no reason to view gay marriage as any more threatening than the relaxation of divorce laws. Nonetheless, the term "marriage" bears such cultural weight that many feel that its meaning cannot be stretched any further. That is why I agree with those who would have the term "marriage" dropped from the law books altogether and replaced with a less pregnant term, such as "civil union."
Religious marriage is another matter. The Jewish term for marriage, kiddushin, describes a specific process by which a woman becomes a man's wife. There is no reasonable way to extend either the term or the process to same-sex unions. However, there may be other options.
A man I met recently suggested that halakha was meant to be an evolving system, but that it was never meant to change as quickly as our current globally integrated society demands. If we attempt to ignore changes in society, we risk cutting ourselves off from the rest of the world. If we embrace change too readily, we risk sacrificing the integrity of the system. Different Jewish communities have found different ways of dealing with this issue, though none does so without a struggle. Judging from precedent, I would say that it is time for the Conservative movement to seriously consider commitment ceremonies for same-sex couples. I would not make such a suggestion for Orthodoxy.
This does not mean that Orthodox communities should ignore or dismiss the plight of Jewish homosexuals. Stigmatization of gay people must not be tolerated. It certainly should not be defended by the statement, "the Torah forbids homosexuality." The Torah does not forbid "alities." It does not outlaw people. It outlaws acts.
Every Jew should internalize the statement of Hillel, "Do not judge your fellow until you stand in his place" (Pirqe Avot 2:5). Straight Jews should try to appreciate the struggles of gay Jews who wish to remain faithful to halakha. Orthodox Jews should watch Trembling Before G-d and read "Gayness and God," by Rabbi Yaakov "Levado" Greenberg. Those who are prepared to accept creative psak should regard homosexuality as a priority as high as that of freeing agunot. The stakes are essentially the same.