These days, it's common not only to see people talking to themselves, but to see them walking along laughing to themselves. This is thanks to the smartphone – and the rise of the podcast.

Islington's Business Design Centre last week (May 25-26) hosted the UK's first trade show for the industry, The Podcast Show.

For those not sure, a podcast is like a radio (or television, for that matter) programme, but without the constraints of scheduling, often free from corporate interference (although not always) and largely unregulated.

In a frenzy of pod-talk, young creatives mingled with media superstars among stalls manned by some of the biggest operators around, including Spotify, Amazon Music, BBC Sounds, YouTube, Acast and Global.

More than 350 speakers took part in on-stage events – including names such as Krishnan Guru-Murthy, Fearne Cotton and Gary Lineker – with live podcasts staged at other venues in the area.

Co-organiser Jason Carter, who was born in Highbury and has family in Muswell Hill, said: "Kicking off at 10am with Louis Theroux and with Alice Levine, who's got a hugely successful podcast, My Dad Wrote A Porno – they are just unbelievable. It was a great kick-off, hence the queues down the road, down to Upper Street.

"We've had big talent moments like Kermode and Mayo – they have a huge podcast – at the Union Chapel. When we went on sale with that show it sold out in an hour, so it shows how popular podcasts are.

"We've had Emily Maitlis down, and Jon Sopel – so we've got big talent."

Maitlis and Sopel have left the BBC and are launching a daily news podcast with Global in September.

For the new project they have joined the new production company of Brexitcast/Newscast/Americast creator Dino Sofos, Persephonica, which has already produced a podcast for Camden's Dua Lipa and is in talks with Richard Bacon.

The BBC is still very much in the business as well though. Jonathan Wall, director of BBC Sounds, announced new podcasts including A Positive Life: HIV from Terrence Higgins to Today, hosted by singer Sam Smith, and football podcast Unbelievable, which will feature Chris Kamara and Ben Shephard.

A common theme when you get "podders" talking is the freedom that podcasts allow, and the speed with which decisions can be made.

For the new news podcast, Maitlis said she and Sofos initially wrote to actor Hugh Grant, such is the podcast "space", who expressed an interest but had to be let down when it emerged "BBC lifer" Jon Sopel would leave to do it.

The Podcast Show itself has been slightly longer in the making.

Jason was previously head of events at BBC Radio and when he left continued to run BBC Introducing Live, working with organisations like Spotify and Amazon.

With partner organisations like that, a show for the "podcast space" (such is the terminology) made sense.

Two years of delays were frustrating, but lockdown did mean that podcasts and the machinery around them blossomed, making use of the coming-of-age of Zoom.

With business partner Tim Etchells, Jason is now based at the Business Design Centre, which he said has benefited from the show's high profile.

"People have flown in from Mexico, India, Holland, Germany, red-eye flights from New York, hundreds from Los Angeles are over, so it's really put a big focus on Islington," he said. "They love the area, the venue's beautiful, Upper Street's amazing."

He said he will be reaching out to Islington Council in the hope of developing the event which is already booked in for May 24-25 in the same venue next year.

"We were in the Islington Assembly Hall six nights and the Union Chapel one night with evening shows but we've got a vision that in three years time, there are parties and events with all these big brands in bars and restaurants all the way down Upper Street," he said. "That's what we want to see. A bit like the Edinburgh Fringe – that's the ambition."

The Ham&High has its own podcast. To hear from guests including Sir Keir Starmer, Dame Esther Rantzen, Juliet Stevenson and Michelle Collins go to podfollow.com/hamhigh/