Aaron makes a dangerous argument, and reaches a dangerous conclusion, in attacking Arizona's religious-liberty bill and criticizing Natalie's post explaining and partially defending it. To take Aaron's odd logic to an inevitable conclusion, if government can force a vendor (baker, photographer, whatever) to participate (by providing a service) in a ceremony that violates his religious conscience, then government can force an institution to provide insurance coverage (providing a service) that covers abortion, violating someone's deepest religious consciences. Religious liberty is the first liberty, the one on which all our other liberties are based. It cannot be subdivided. In the cases that spurred the Arizona law, nobody was refusing a public conveyance (much less sustenance) to anybody else based on some immutable characteristic such as race -- indeed, nobody was refusing a public conveyance even to somebody based on homosexuality, which is a status defined by activity, not by visible inherent characteristics -- but, instead, they were denying a service that would be used in support of a particular ceremony to which the provider objects on specifically religious grounds. Again: not a characteristic, but an action. This is precisely what the Little Sisters of the Poor and Hobby Lobby object to doing with regard to abortifacients, and with good reason. The principle is exactly the same. The principle, recognized in the United States since the early 1790s (and in Virginia since 1776), based on a principle at least partly established by the Glorious Revolution of 1689, and in Anglo history at least rooted even further back than that, is that to force somebody to take a specific action directly against their explicitly religious principles is to engage, unambiguously, in tyranny.
To Aaron's example of a Muslim cab driver refusing service to a Jew, or whatever, again, so what? Unless that single cab provider is a monopoly, then it's no big deal. In fact, I have used a very similar argument in just the opposite direction: I guarantee that if government tried to force a Muslim photographer to work at a jewish wedding, or to force a Muslim restaurateur to cook pork dishes, the Left would be out in full force defending the Muslim. And in this case, for once, the Left would be right. It is the Muslim's absolute right to deny a service or a particular product -- not all sustenance or a conveyance -- against his faith.
Otherwise, the religious clauses of the First Amendment are nil.
So, Aaron wants to avoid maltreatment of homosexuals. Good for him. But the answer isn't to maltreat a faithful traditionalist Christian.