I'm a conservative Roman Catholic, who views homosexual activity as mortally sinful, and would prefer to live in a traditional Catholic monarchy where the monarch is answerable only to God and the Pope. I don't expect anyone on Slashdot to see eye-to-eye with me here, and this is not the point that I wish to debate.
I realize, however, I live in a modern, liberal, pluralistic republic, and will likely never get to live in a society that I want, therefore I am more than willing to compromise to be at peace with the rest of society. I feel in a secular republic, such as the US, the best solution is for the government to stay out of it -- best would be no legal recognition of marriage at all. Nor should it recognize anything resembling a civil union. Marriage, from a legal standpoint, should be built out of pre-existing contract law. Simple and elegant -- Catholics could have a standard marriage contract drawn up that would fit their framework, Jews could do the same, as could atheists, Freemasons, Jedi, etc. Employers would be free to do what they wish in terms of insurance -- if you don't like it, work somewhere else.
Unfortunately, this would require serious amount of changes at the federal, state, and municpal laws, including modifications to the US constitution. I would certainly support this sort of effort, though it is unlikely to ever happen.