Guys
A receiver is exactly that! I'm no engineer but I believe that it shouldn't make any difference to most aircraft (sure someone will correct me).
5miles baby - A mobile phone however is a receiver and a transmitter. It is the transmitting part that we don't like. It interferes with the radios and other equipment. Take for example your mobile phone in the car or at home. Whenever it changes its local cel or is switched on it will update itself. It is this noise that you will hear through the speakers and what we hear through our headsets. This can be extremely distracting especially when you have more than one mobile updating and in busy airspace.
Personally, I don't have a problem with someone listening to their radio or using GPS. However, I ask that it is turned off for take-off and landing. These are critical phases of flight and I wouldn't want to take any chance that something just MAY set something off or interfering with the instruments.
With regard to the cc on a flight. They may view it that if another pax saw you using it they may get their mobile phone out and start using that or may get distressed thinking that its a remote device for some sort of no good
At the ed of the day it's each to their own and some airlines may have different policies on the subject.