@Backpacker: yes, I generally agree, but it does vary between fields. Largely generalising: French speaking pilots seem to find it quite natural to address one another, and I've heard them do so quite casually and to good effect. And I'd not be surprised to find the same in Italy, Spain, Portugal. German speakers OTOH seem to prefer a central authority...
Still, I should like to warn against the use of non-standard phraseology. Or do we need to be reminded why ELP was introduced..?
And even more prominent, again: not every aeroplane carries a radio, or to good use.