Mr Weallans - a shaggy-headed 20-year-old, whose mischievous exterior conceals a frantic, hard-headed talent - chuckles as he recalls: "I had to sign all their T-shirts."
Why all the attention? It could be the result of stubborn hard work reaping success from crushing financial failure. It could also be his eye for a blossoming market. But underpinning all this is a combination of technical wizardry and an ability to keep a young, sophisticated and discerning crowd of clubbers happy.
Advertisers targeting the 16-24 consumer goldmine have only just begun to realise the throbbing potential of the clubbing industry. But Mr Weallans is only too well aware of it. He now employs eight staff, mostly British teenagers, to run his ventures abroad, including several large clubs in Ibiza.
He is amused by his success. "I had two friends I'd known for ages, and I was at a party just before A-level results time. I said to these lads: 'Why don't we just do video?' And we did."
In his early teens, he used a family Omega computer to create cartoon characters. When he was given a camcorder, something "clicked", he says. He was already assiduously collecting images and video clips. But it was a failed career as a pop guitarist that sparked his current success.
"I was in this band, and I'd always thought bands were very boring live. We had a drummer who was a much better juggler than a musician, and would insist on juggling halfway through the set. You can see why it didn't take off."
Coming back from a recording session, Mr Weallans stopped off at a U2 concert in Cardiff, and was hooked by the potential he saw in multimedia. "There were awesome displays of video," he recalls. "They had a link to Sarajevo, and then they tried to call up Margaret Thatcher. It blew my mind."
He had already applied to the Prince's Trust for money to buy a projector, and the next step was to convince a bank to give him pounds 40,000 for a Glastonbury gig he had wangled. "I was 19, with no credit history, and I was a new kid on the block, with only one small screen. [Glastonbury] was the biggest tent in Britain. It was like going to an Odeon cinema and saying you had a lovely big TV, were they interested?" He pulled it off at the eleventh hour, creating a cult mix with clips from Thunderbirds.
But the work did not flood in and he still had a big debt to pay. Fortunately, a Ministry of Sound scout spotted him and invited him on tour. Working around the world with the club taught him some valuable lessons. "It was the first time I had to be branded. They are very protective about how they portray their name, and the rules are different. It was pretty intimidating. But they're good at backing people from nowhere."
In a small market - he reckons there are less than a dozen serious competitors - he is already building global networks. "The industry's a bit volatile, and a lot of the time you're dealing with people on the end of a phone. It's not like selling insurance. The whole idea is that you make videos which complement the music. The human body doesn't just have ears; it has eyes. It's a complete experience. Most other people record their stuff, but in my case, it's all live."
Mr Weallans is keenly aware of the possibilities for his art; on the internet, in clubs abroad, and in advertising and sponsorship.So far, he has done well, but it remains to be seen whether he can create a sustainable advantage by thinking strategically. All the signs are that he will. "You learn not to think small," he says. "Also, I've learned not to give up by any means. That's where most people go wrong."