Completely agree with Rhino.
Of course we can get back to the sticky subject of those with an altered state of mind having control of someone's life...but for the sake me not posting something really lost, let's not (for now).
However, I do have a question. DNRs are just too narrow for me, I don't think I'd ever sign one. However, if in a will you state that you don't want to be kept on life support in such and such situations, or if you tell a close family member, how does that play out? I would assume it's still under jurisdiction of state law (in which case I've move to Oregon). Should it be? I think it's apparent that I think not. Then again, we get into more hazy lines and such with being able to verify that said person was okay with whatever they chose.
So in my perfect world, (unless this already exists) there should be a legal document that people must make after the age of 18 specifying terms of their death in extraordinary conditions. Yes, I realize the age can be debated on, but it would land basically where a person is capable of making their own decisions knowing that they will actually impact their life. I would say earlier rather than later because then the document would be pointless to have. And of course, you may edit it anytime you wish. You should also have some very close family member with you so that it's not just on paper, but spoken aloud as well.