I think it should be a personal choice, some people are for and some are against and I bet peoples opinion would definately chance if they were faced with that situation.
They do it to animals - they should be able to do it to humans under their own consent. I think the biggest issue is people who are crippled, who cannot make that decision but their family members argue they should be put to death.
I suppose this should be allowed... I mean, hell. If I had to choose between 3 months of intense pain and hating my life then dying, or just falling asleep, dreaming for a little while, then dying.. I would choose sleep.
That also would be incredibly painfull, face first in blow. I dont think death gets any worse then that, other then drowning or burning to death. I mean cocain is just like.. I dont know, realy gritty flour. Seems incredibly painfull to do, much less die of.