Answers to Cstork's questions:
1. The one-way valve is a way to prevent the spread of diseases. Also, having a guy puke on you may cause you to gag too and you may not be able to continue performing CPR. It's tiring as it is, gagging probably wouldn't help matters. I would use one if I had one with me. If I didn't, I'd perform CPR anyway. but it's a good thing to have.
2. I would definitely get someone to a hospital as quickly as possible after resiscitating them. Now, if there is danger of a spinal or neck injury it is critical to avoid moving the patient as much as possible. if possible, get someone to phone for help, or go get help. if in a wilderness situation, make a stretcher to bring the person out if absolutely necessary. I would say the emergency situation is less extreme if the person starts breathing again, but it is still an emergency.
3. It is pretty easy to find a pulse in the neck- even if a body is in shock, blood will still pump to the brain even if it stops pumping to the extremities. If you detect a pulse, give rescue breathing, not CPR. Don't spend TOO much time trying to find a pulse if you don't detect it at first. try 2 or 3 times maximum. count to 10 each time you attempt to find the pulse (sometimes the heart is beating slowly, but it should beat at least a couple of times in 10 seconds.) then do CPR. (I just took my CPR refresher course last week, it's fresh in my mind!!!)
4. the official requirement to be certified in CPR is to get a refresher once a year. It's not that expensive and only takes a couple of hours. If that seems like too much, get recertified as often as you can. My Wilderness First Responder certification needs to be refreshed every 3 years. I would say that even if I didn't get the CPR re-cert every year, i would get recertified every 2 or 3 years. the requirements change fairly often and it's good to have CPR fresh enough in our minds that we don't have to think about it too much when the emergency arises. This year there was one change about abdominal thrusts (used to be called the heimlich maneuver) for an unconscious victim, and for me it had only been a year since my last certification!!!
I guess that's my 4 cents, definitely more than 2 cents

Lauren