There's no debate necessary. When in a theater or concert hall (or at events like weddings and funerals), turn the ringer off. Period. If you are a "must-carry" kind of person (on-call surgeons, for example), then get a phone with vibrate feature -- most phones have this now, some by using an optional battery. On a similar note, heaven help you if you phone goes off on the golf course while I'm in the middle of my backswing... you'll be wearing my club.
As for etiquette, when using your phone in public, remember that you're in public. If the conversation you're having would otherwise be inappropriate for the setting (either in content or volume), then it's inappropriate to have the same converstaion on your cell phone.
Finally, always respect any rules/requests about cell phone use made by the proprietor of the establishment you are in. In some cases (hospitals, for example) it is a safety issue; in others, it is an expected courtesy toward your fellows.
Sorry Tiger! You should have your caddy do it for you.
Overall I agree with your post except that comment.