The David Dimbleby lecture delivered by Tony Robinson on behalf of Terry Pratchett discussed assisted suicide.
Personally I am for it if it only applies to Terminally ill patients with chronic pain with no further chance of survival. If it is what they wish then I think they have the right to make this choice.
After all if a pet is in permanent discomfort with no quality of life we put it down and call it 'humane'.
What is right in keeping people alive just for the sake of it?