Few characters are more suited to working for a brand such as Virgin, with its reputation for transparency and willingness to agitate established markets and practices.
Virgin's activities invariably provide journalists with fresh, engaging copy. Even Virgin Mobile's stock market flotation added a little colour to the traditionally grey world of City reporting last year.
At the conference, Day will share his perspective on the media circus that greeted the float, but he will also warn that the reputation of the company as relaxed and open can sometimes lead outsiders to underestimate its professionalism.
When Virgin Mobile launched in the US in 2002, Day was astonished to hear people asking where the beanbags were. 'It made me laugh. It is a high-pressure environment. Virgin Mobile is thoroughly professional but not bureaucratically professional,' says Day, explaining that it doesn't 'let processes get in the way'.
Laid-back and accessible, Day has a naturally cheerful disposition. His conversation is free-flowing and unstifled by his responsibility to shape perceptions of the company. However, he insists that he does worry about what he says.
'I'm paranoid about it, I lose sleep. But that's my job. I find it ridiculous that some directors of communications don't speak to the media,' says Day, adding that he is encouraged to bring his natural flair to the role.
'Richard Branson said to me: "Don't be afraid to make a mistake, but always learn from it." There are few jobs that give you so much opportunity to be yourself,' he says. 'I like smiling. I like enjoyment. I like a life rich in experiences.'
While Branson celebrates the success of the first solo non-stop flight around the world, which he funded, Day is a little less grand in his ambitions.
He is currently planning to fly around Britain in a day in the small plane he co-owns. He sought his pilot's licence following a friendly challenge while stuck in an icy tent 18,000 feet above sea level on a press trip to cover Bear Grylls' attempt to become the youngest person to scale Mount Everest.
'I love the space and peace,' says Day, who flies most weeks during summer.
An outdoors enthusiast, the burly 38-year-old Wiltshire resident admits he's not the climber he once was, but insists he can enjoy the same feeling of escapism from a walk in the park.
John Cassy, who worked alongside Day as a journalist at the Daily Express, says his 'personality hasn't changed at all' to fit in at Virgin: 'He's sociable and very good company. He has a relaxed demeanour but he's a very driven bloke who gets things done.'
Cassy, now channel manager at Sky TV channel Artsworld, believes Day's creative and entrepreneurial skills and his ability to find news angles were fostered at Express Newspapers, where 'we had bugger all resources', and make him a perfect fit at a 'challenger' brand like Virgin.
'Steven's competitive in a good-natured way. I'm sure he enjoys winding up his competitors and I hope they take it in the right spirit,' he says.
Such antics have included sending rival 3 a birthday cake decorated with 'Many happy (handset) returns', while a T-shirt with mock 3 branding celebrating Virgin Mobile's third birthday hangs proudly in his office.
As a journalist, Day was attracted to exposure to different industries and issues and 'becoming an expert for a day'. But the opportunity offered by Virgin to witness a single business being built from scratch was too good to pass up.
Now six years into his PR career, Day found it fascinating to see media coverage of the Virgin Mobile float fluctuate from positive to negative, seemingly at the whim of journalists.
'It was a particularly interesting experience. I have been the architect of that kind of switch in the past,' says Day.
No doubt he'll have plenty to say on the issue at the PR and the Media conference, and delegates should be aware that beneath his uninhibited style, Day is conscious of every word he utters.
1991 Editor, Homes and Saving (Halifax magazine)
1993 Reporter, Sunday Express
1995 Money editor, Sunday Express
1996 Money editor, Daily Express
1997 Business editor, Sunday Express
1999 Joint deputy editor, Sunday Express
1999 Head of PR, Virgin Mobile
2000 Director of corporate affairs, Virgin Mobile