There are three stages in owning a mobile phone. You start off feeling chuffed at having entered the brave new world of telecommunications; this quickly gives way to grave embarrassment whenever the phone rings in public; eventually this is replaced by a period of quietly showing off.

I'm now in the third phase, engaging in boring conversation about battery life, dead areas, etc. For example, everybody knows that you get a decent signal in Calais (it fades by St Omer). But I discovered that you can also make a call from the Cotentin peninsula in Normandy, presumably via the Channel Islands.

A few years ago we awarded a prize to the person who picked up Radio 4 on long wave the farthest distance from these islands. I think the winner heard the old Home Service in Iraq. It would be interesting to know the most distant place in which you have successfully used your mobile phone. Please write.