Cell phone usage in doctor's offices, stores, restaurants, etc

Don't you think it rude when you're sitting in the doctor's office and the person next to you starts talking on their cell phone?  So, there you are, trying to read a magazine and the person to your right is doing the "he said, she said" conversation.  Annoying at the very least, rude to the max!  Most people don't even realize we talk louder the moment we pick up the phone. 

Or,  you're grocery shopping and someone is right behind you talking and it sounds like they're talking to you.  Nope, they have a head-set on and are chatting away quite nicely to some invisible person on the other end.  I've been known to respond to them until I realized they were talking into a wire thing!!  They don't care! 

Then there's the person in the restaurant, just "has" to take that call.  You're on a romantic date and this person is the next table over talking about stocks and bonds.  Almost forgot, have you ever been in an elevator and someone is chatting away, oblivious to their surroundings?  That takes the cake for me!

Do any of these people realize they're not alone in the Universe; that there are people right next to them?  If you were with a person, you would be lowering your voice so's not to bother others yet, if on a cell, you talk all the louder!!

Are you one of these people?  How do you feel about doing any of the above or do you think people ought to accommodate you?