Over at Volokh, there's a discussion of it, mostly as relates to applying it to overly exuberant miscreants of the type who believe in making up in quantity, for example, what their deeds lack in quality. Also brought up is the subject of physician-assisted suicide.
This is a touchy area, and peoples opinions vary greatly depending on how the question is phrased.
Folks, if you're looking for help in shuffling off the mortal coil, you probably shouldn't be consulting with a physician in the first place. Doctors, after all, get paid to keep you alive. Talk to an Engineer. One who has had to sit through weekly production planning meetings will probably sympathize with you.
Engineers actually get paid good money to come up with devices specifically designed to hasten the demise of humanity, sometimes in wholesale quantities. They are also the ones who understand some of the "undocumented features" of otherwise innocuous devices you can find almost anywhere.
Just remember to ask discretely, as this sort of service is not always looked on favorably by the local authorities, and expect to have to pay in advance.