Lord of the rings star Billy Boyd happy to be promoting glens of his homeland

PERHAPS not quite as awful as being kidnapped by Orcs, but rolling down a hillside in a giant hamster ball does sound rather like the kind of mishap that might befall an unwary Hobbit in Lord of the Rings. Billy Boyd, the slight-framed Glaswegian actor who played Pippin in the blockbuster film trilogy of Tolkien's epic, goes wide-eyed at the prospect, as if newly confronted by an Ent: "They tell me they put water in the ball as well; I don't know how that's supposed to enhance th

We're discussing "sphering", or "zorbing", as it's known in the trade – the increasingly popular pastime of rolling down a hillside harnessed into a 12ft diameter cushioned plastic ball, apparently one of the most popular activities for Cumbrians holidaying in Scotland, as if you didn't know that.

This odd demographic concerning an even odder pastime emerges from an online survey of holidaymakers' favourite activities in Scotland, published last week by the tourist board, VisitScotland, who enlisted Boyd to help showcase the results.

Boyd is nothing if not game for anything: when we last spoke, in April, he had been all but thrown into touch by some hefty rugby players as part of his charity role as an ambassador for the Princess Royal Trust for Carers , he has practiced martial arts and remains a keen surfer. Zorbing, however, does not as yet figure in his, er, sphere of activities. "But I might have a go. It does sound like something that might have come from New Zealand," he grins, referring to the country where he spent some 18 months making Lord of the Rings and helping to boost that country's tourism industry in the process.

Now Boyd is happy to lend his name to promoting the glens, bens and sometimes eccentric leisure activities of his homeland. The top activity, according to VisitScotland, is viewing dolphins in the Moray Firth, with seaplane flights from Loch Lomond a close second. Sphering didn't actually make the top ten, but a regional breakdown of visitors suggested Cumbrians nurse a strange proclivity for it, just as Mancunians apparently like Loch Ness Monster-hunting while Liverpudlians seek out locations from The Da Vinci Code.

Boyd cheerfully admits to not having chalked up any of the top ten activities, but he does love surfing – be it in Mexico or Machrihanish. "I get out as much as I can," he tells me. "Probably not so much since we had the baby (two-year– old Jack who he has with his partner Ali McKinnon]. But I still love to get into the water and I always feel better once I've had a little surf. Machrihanish on the west coast, Pease Bay or Coldingham if I go east. If you get the right direction of swell it can be just beautiful there, as good as I've had anywhere, and with nobody else in the water."

On the domestic front, so far as Scottish holidays are concerned, he says he and MacKinnon, a dancer, like to visit St Andrews, while he also has a soft spot for the Ardanaiseig Hotel on Loch Awe, where he proposed to her.

Chatting to me in an Edinburgh hotel, comfortably casual in jeans and a striped collarless shirt, he looks nothing like a man fast approaching 40. Boyishly affable as ever, he appears delighted to be promoting home tourism: "I don't really do much promotional stuff but I felt that with this one I could be honest. I love to travel, and I've been lucky in that my job lets me do that, but I'm very proud of where I come from, and I get very excited if a friend comes over and I can show them round."

When we met, he was relishing the prospect of a little excursion of his own – to the Wickerman Festival near Kirkcudbright with his band Beecake. While he stresses that acting is not taking a back seat he concedes that the group, in which he sings and plays guitar alongside long-standing childhood friends, is his current preoccupation. After Wickerman, they were returning to Chem19 studios in Blantyre where they have been cutting their first album.

Managing the music as well as the acting can pose a certain balancing act, he agrees, which is one reason why he's anxious to make "the very best record we can. It's hard to be thought of just as an actor who plays music, because you're seldom taken seriously. One newspaper said it was just a vanity project ..." he grins: "That's almost what we called the album."

He's not the only former LOTR star to venture into the music studio. Viggo Mortensen, who played Aragorn in the trilogy, is also a musician. Boyd, who describes him as " the ultimate renaissance man", played drums on one of his recordings, so is thinking of recruiting him for his band's video by way of quid pro quo.

Like most of the core cast of the trilogy, Boyd bears a tattoo of the "Elvish" symbol for nine – a reference to the nine members of the fellowship of the ring. But having made his name in what became some of the highest-grossing films of all time, his film work since has been lower key – On A Clear Day, with Peter Mullan, and The Flying Scotsman biopic about cyclist Graeme Obree – but he counters any perceptions that he's been sitting on his laurels.

"There is a bit of that in the press: 'Why don't you jump on the things you should be doing?' and all that. It doesn't really worry me, you know?" – he sounds only mildly piqued. "The most worrying thing for me would be if I was lying in bed thinking, 'Oh, God, I've made a load of shit,' you know? And I don't feel that."

He currently stars alongside Charlie Cox, Robert Carlyle and Kate Mara in Stone of Destiny, Canadian-based director Charles Martin Smith's film about the four Scottish nationalist students who repatriated the Stone of Scone from Westminster Abbey in 1950. Due for release in the autumn, it received something of a panning when it was premiered at the Edinburgh Film Festival last month.

Boyd is defiantly upbeat about it, however, attributing criticism to "that strange Scottish thing that it had to be given a hard time simply because it was made by a Canadian director and starred a guy from London and a girl from LA, which I find weird. I think Charlie Martin Smith is brilliant, and the film only got made through his passion for it." It remains to be seen whether or not box office takings will back up the critics.

He has another film due out by the end of the year, Glenn, a psychological drama involving two pianists, a robot and an obsession with the Canadian maestro Glenn Gould.

Meantime, he periodically visits his friend and former fellow-Hobbit, Dominic Monaghan, in Los Angeles, where the pair have been working on the script of a comedy film which he describes as being about two Britons at large in the United States, and with something of the old Hope-Crosby Road To ... movies about it. "We'd like to get a good producer we really believe in , and we feel it will happen."

Brought up by his grandparents after he was orphaned in his early teens (hence his interest in the Princess Royal Trust for Carers), Boyd trained and worked as a bookbinder before entering the Royal Scottish Academy of Music and Drama at the relatively late age of 24, which, he reckons, predisposed him to savour every minute of his time as a drama student. "I don't think I missed a day while I was there." Which was why, in May, he added his signature to those of other RSAMD alumni such as James McAvoy, David Tennant and Robert Carlyle to a strongly worded open letter to the First Minister, demanding action over the college's critical financial situation that was threatening staff redundancies and other cutbacks.

Conscious of his 40th birthday looming next month, the conversation turns to as yet unfilled ambitions. He'd like to try his hand at directing, he says: "I love making films in Scotland, and I wish there were more Scottish stories being told – they don't have to be Braveheart. I like watching little films ... sometimes French ... just slices of life. I loved what Bill Forsyth did with Gregory' Girl, or Local Hero, and I'd love to direct that sort of little bit quirky thing, real life but cranked up just a couple of notches."

Anything else? "Before it gets too late, you mean," he chortles. "Maybe roll down a hill in one of these balls, before my hip gives way."

• For further information, see www.myspace.com/beecakeband and perfectday.visitscotland.com