Ran into former colleague on train (or rather on platform), where he was eking out the last traces of nicotine from cigarette before he boarded the train.

Former colleague's most celebrated claim to fame was setting office on fire by throwing unextinguished cigarette butt in bin of highly flammable things, resulting in fire brigade being called out and neighbouring offices evacuated.

"Hello Colin," I said, getting on to the train. "What are you up to these days?" He didn't answer until a few minutes later when the guard came and told him that the train was about to go and he'd better get on.

So, having had one last drag he came and sat next to me. Colin is now a freelance journalist, doing a bit of this and a bit of that, a bit of writing, bit of radio and a bit of voiceover work; for which he is in some demand, due to his resonant but gravelly chain smoker's voice.

You can hear his Marlboro tones on local radio telling you that you can get three Big Macs for the price of one and on various telephone exchanges informing you that all the lines are busy at the moment but your call is being held in a queue and will be answered as soon as possible but in the meantime would you like to hear about the special offers, etc etc.

You can also, Colin informed me, detect his voice on the London Underground, telling you to mind the gap and that the next train to Walthamstow will be arriving in three minutes.

The latter, he explained, are recorded as separate words. So, he will spend a morning in the studio recording lines such as; "The next train to", "the train approaching", "the train now on platform", "will be going to Walthamstow", "four", "the delay", "three", "will terminate at", "three minutes time", "is running late", "Kings Cross", "four minutes", "we apologise for", "five minutes", "is delayed", etc etc.

It is then apparently up to the station officer on any given station to string all Colin's efforts together on a computer and make a complete sentence relevant to the particular train. For example, using a selection of the above sentences, he could construct; The train now on platform - four - is running late - we apologise for - the delay.

The effort of explaining to me why the announcements on tubes are so disjointed left Colin gasping for a cigarette and, since the train had stopped for longer than scheduled, he decided to hop off on to the platform for a quick drag.

He returned several minutes later, as the train started making going noises, slightly less twitchy for it.

But by East Croydon he was showing all the signs of an addict who has not had his fix again and claimed to be travelling to London Bridge so would be changing here.

He got off the train and lit up, leaving me suspecting that he didn't actually need to change trains but just needed the excuse for another fag.

So I was surprised when I reached London and was making my way down the steps to the tube to stumble upon an extreme case of pots calling kettles black.

"Please remember," said a sanctimonious, tannoyed voice which I now recognised as Colin's, "there is no smoking on the underground at all times . . ."