Simon Kelner: National Trust's earthy delights for strollers in Soho

On its website, the National Trust gives just the sort of advice that you'd expect. "With longer, lighter evenings," it says, rather hopefully, "there's never been a better time to head out and enjoy the summer landscapes."

Or: "We love the outdoors and there are plenty of outdoor adventures waiting for you." Both these exhortations, you might think, apply to a stroll in the woodlands, or across rolling hills. But no. The National Trust clearly has more earthy delights in mind.

It has just launched a mobile phone app called Soho Stories, which is designed to bring, in their words, "60 years of Bohemian Soho to life". The app is free, is narrated by the man of all parts, Barry Cryer, and uses GPS technology so that, wherever you are in London's fleshy underworld, it will give you a tale of relevance to your location.

It's a genius idea. On downloading the app, you are warned about "strong language and references to sex and violence", although I found little that would jam the BBC switchboard were it broadcast before the watershed.

Unless, of course, your children (or indeed, you yourself) are frightened by Janet Street Porter. There she was, telling tales of the Groucho Club from a period when the artist Damien Hirst would regularly brandish his penis in the bar. "He took it out so often," said Ms Street Porter, "that no one would notice after a while. It was quite small anyway," she added, charitably. Anyway, the purpose of the app is that you can stroll the streets of this hedonistic quarter, the home of "dandy writers and woozy poets, rackety drinking clubs and jazz basements", as Barry Cryer put it, and pick out where Jeffrey Bernard drank so much he was frequently unwell, or where Courtney Love found her inner lesbian, or where Francis Bacon would take his consorts for a drink, or where Ronnie Scott brought American jazz to Britain for the first time.

I have been lucky, and reckless, enough to have visited many of the establishments on the Trust's grand tour, and many of the stories have passed into Soho folklore. I particularly liked the reminiscences of the gloriously named Roxy Beaujolais, who was a waitress at Ronnie Scott's Club in the 1970s and had to listen to Ronnie telling the same joke night after night. "Don't forget that George Melly is appearing next month," Ronnie would announce in a voice steeped in Rothmans. "So make sure you get your tickets, because the last time he appeared, a lot of people were disappointed." He would pause..." and some people couldn't get tickets." Boom, boom, went the band.

This app marks something of a departure for the Trust, and it has predictably upset some of their traditionally minded members. But the organisation's raison d'être is to "preserve and protect historic places and spaces". It's not too much of a stretch to extend this to people. Put it away, Damien!