I think one failing of CPR training is not pointing out that the victim may likely die. I have heard that about one-third of all attempts are successful. True, a lot of things can go wrong - fractures of the sternum are common, even by EMT level practitioners - but the alternatve is even worse. A really alert aider when faced with the likelihood of spinal injury, will use the jaw thrust maneuver to open the airway.

Myself, I have a perfect record - two for two. In both cases, the victims were dead by the time I had the oportunity to administer my healing arts.

All of the various gizmos mentioned in this thread may be of some use, but I think there is no substitute for regular training by as many people as possible - an opinion that gains in strength as I grow older and older.