Re: Ah, yes. The dreaded "fix it NOW!" call ...
Don't know if it still works but, back in the day wrapping the phone in tinfoil (a good use for any scraps leftover from hat making) while switched on would mean anyone calling got the message 'it has not been possible to connect' instead of 'this mobile is switched off' so there was a plausible excuse that the signal had just dropped out.