Interesting subject and one that in these days of blossoming blame culture people's decision one way or the other will be judged all the more harshly. I've got a fear of needles, numerous things such as having my eyelid anaesthetised and sewn back together have meant i'll never give blood as long as i live and if i die in the back of an ambulance through loss of blood those who think me selfish can consider it come-uppance and dance on my grave.