For all interested parties, the American Heart Association has officially changed the standards on how to preform CPR in the field. Traditionally, the method has been ABC (airway, breathing, compressions), but they are now putting chest compressions at the front of the sequence, mainly because the most common cause of patient collapse is some sort of cardiac arrest. They now recommend CAB to get the blood flowing.
You can read a lot about it here: http://circ.ahajournals.org/content/vol122/18_suppl_3/
It's a journal entry about the updates.
Or, if you want to read a little about it, just do a Google news search for CPR.
Here's a fun fact from the article: "Fewer than 50% of persons in cardiac arrest receive bystander CPR. There are probably many reasons for this, but one impediment may be the A-B-C sequence, which starts with the procedures that rescuers find most difficult: opening the airway and delivering rescue breaths. Starting with chest compressions might ensure that more victims receive CPR and that rescuers who are unable or unwilling to provide ventilations will at least perform chest compressions."
I can understand a bystander having a physically difficult time trying to keep an airway open, but I can't imagine seeing someone collapse and thinking, "shit, that guy looks like he needs help. But, man, I don't know about puttin' my mouth on his mouth. Sounds pretty icky."