Do you really want to settle this one? I might be on to something.
I personally don't beleive in marriage. I feel it's a nonessential ceremony symbolic of institutionalized control. It has no bearing on true love. If you love someone, saying you love them and knowing you love each other should be enough. What matters in a relationship is how you feel about one another, not whether or not rings and vows are exchanged in some ceremony. One would argue that you must join together in the eyes of God. Well, correct me if I'm wrong, but God is omniscient and omnipresent. God sees everything. You don't need a ceremony for God to see your love for another person. If anything, God should come down and smack you on the head for marrying someone for the wrong reasons.
Okay, now that my rant on marriage is out of the way, let's get gay marriage sorted out. Essentially the arguments against allowing gays to marry are deeply rooted in religious beliefs. Okay, perfect. That works for me on some level. Let's run with the idea that marriage is a religious entity. Get rid of marriage as a government issued relationship status. Leave it to the religious ones to get hitched. No tax benefits. No nothing. Change hospital ethics policies on spousal rights. The effects of this kind of distinction are far reaching. It's now just a ceremony in the eyes of God. Anyone of the agnostic or atheistic persuasion shouldn't be able to get married, but rather grant them civil unions or create a new government relationship standard that allows tax benefits, etc that everyone is allowed to participate in. Then you take away any religious undertones about two men or two women being together in marriage in a legal setting and the courts will decide once and for all what we can do about this dispute.
You either piss off all the heterosexual couples that aren't religious and we finally get down to solving this dispute or everybody gets what they want. Take the religion out of politics. It's much easier to get things done. Change the entire dynamic.