Catatania, Stereophonics and the Manic Street Preachers are more famous than any male voice choir ever was, and even Catherine Zeta-Jones has finally made it off British TV screens and into Hollywood.

But you could see Lawrence Llewelyn-Bowen

Photographer Sian Trenberth is finding the scene expanding so fast, she has had to start a second volume of her portraits of the 50 greatest Welsh celebrities.

But leading the global charge of Welsh cool is Sws, a fashionable social club which means 'kiss' in Welsh and stands for Social, Welsh and Sexy.

The club began in London four years ago in the fashionable Groucho Club in Soho, as a small party of 70 trendy pals.

Now it boasts a membership of 1,200 Welsh glitterati - mainly high-flyers from the world of arts, media and politics - who meet in London for monthly parties.

They even have their own website

Sws was founded by actor-director Stifyn Parri, who said that when he first moved to London, his Welsh friends began to play down their identity as a social group who liked having fun.

"When I first came here I noticed that all my friends had sort of disappeared and faded into the background," he said.

"The Irish used to meet up at clubs or pubs and have a damn good 'craic'."

"And we have this word 'hwyl' which is the same meaning as craic, but I didn't see anybody having it."

Ffion introduced William to the joys of Sws

He added: "I was a member of a lot of Welsh societies in London that didn't seem to reflect my attitudes towards being Welsh, so I thought - well, I'll start my own".

The club says you don't have to be Welsh or even sexy to join, just interested in Welshness.

It even welcomes those who perhaps sound very English but want to come out of the closet as a Cool Cymru.

"I don't sound like the archetypal Welshman but I've been brought up to believe myself very Welsh," said interior designer Lawrence Llewellyn-Bowen.

"And I'm transferring that now to my daughters. They're little Welsh girls".

The ultimate in global Cool Cymru?

However, some seemed worried that it was all becoming a fad.

"I'm a bit nervous about this 'Cool Cymru' and this fashionable thing," said actor Ioan Gruffudd. "Things go out of fashion. I hope this is a positive thing which is here to stay, and not just some sort of passing phase."

Ffion Jenkins was a member before becoming Mrs William Hague. Veteran actress Sian Phillips is president and weather girl Sian Lloyd is a member. Notting Hill star Rhys Ifans apparently puts in an appearance at the parties every now and then.

But most A-list of all is Catherine Zeta-Jones, who is now heading the charge of Cool Cymru across the Atlantic.

Swansea-born Catherine, 30, has agreed to become patron of the new New York branch of Sws. She is expected to take along boyfriend Michael Douglas to their first American meeting next month.

And you can't get much cooler than that.