Elijah Wood: Kicking the hobbit

"This festival is amazing. I've wanted to come here for so long, and to be here for just a night is torture." Wood shakes his head and blows ruminative smoke at the window of the hotel suite, his surreally luminous pale-blue eyes gazing out at the castle plonked in the middle of the city centre. The bands will have to wait.

The various festivals taking place in Edinburgh in August make the city the main destination for the arts globally. And in terms of box-office clout, the Lord of the Rings trilogy makes Wood the biggest star attending this year's 59th International Film Festival. He's one of the most striking actors of his generation, the diminutive boy/man who will forever be Frodo Baggins. But in the low-budget Green Street, he is memorably cast as Matt Buckner, a well-to-do American recently kicked out of Harvard who, as if by cinematic magic, becomes a well-respected member of a West Ham "firm", the Green Street Elite. Matt's newfound enthusiasm for boozy rucking impacts grievously on his sister, her English husband and the latter's terrace tearaway brother (Charlie Hunnam, the young one out of Queer as Folk).

While the plot is a little fantastical, and the subject matter somewhat worn, Green Street is well acted and emotionally involving. And, unsurprisingly, violent too - one actor suffered a broken nose during filming. The fight scenes are vivid, shot with jerky, close-quarter camera work that leaps out of the screen. It won't only be legions of female and fantasy fans who will wince as "Frodo", having downed umpteen pints, is viciously smacked to the ground before getting back up and sticking the boot in himself.

As a committed music follower, and having formed a close bond with the other hobbit actors on Lord of the Rings - complete with matching tattoos - Wood was drawn to the themes of tribalism and gang fraternity in Green Street. His accent betrays no hint of the Iowa he left as an eight-year-old when he, his mum, brother and sister swapped the Midwest for Los Angeles and the pursuit of an acting career that began with a Paula Abdul video, a bit part in Back to the Future Part II, and a role in Barry Levinson's Avalon. His dad stayed behind in Iowa (he never mentions him), and Wood rhapsodises about his mum's "instinctive" wisdom on how best to guide him through a Hollywood that eats up child actors. It was her keen eye for what was "right and pure" that allowed him to progress through roles in Flipper and the critically mauled North, via The Good Son alongside child-star flameout Macaulay Culkin, on to a breakthrough part in The Ice Storm and, ultimately, aged 18, the beginning of the four-year Lord of the Rings shoot.

But with Elijah Wood, before you get to hobbits and hooligans, you have to talk music. It relaxes him, excites him and, frankly, is a lot more interesting and illuminating than Orlando Bloom, Josh Hartnett or somesuch young buck wittering on about their "craft". Wood has been making films for a decade and a half but his love of bands seems to be hardwired into his genes. (I'd brought him some CDs of fairly obscure British stuff I thought he might like; the little bugger already had most of them.)

Yep, he's up to speed on the new Franz Ferdinand single, "Do You Want To?" ("I heard it on Jo Whiley," he says like a native), and pronounces it "quite disco"; they were his favourite new band of last year but he seems not sure what to make of their apparent new direction. He talks enthusiastically of meeting Radiohead's producer, Nigel Godrich, in Los Angeles the other week but was alarmed by news from him that he shouldn't expect a new album from the band until next autumn. "Which is a bit of a shame." The most exciting thing that's happened to him of late was taking his mum to see The White Stripes at LA's Greek Theatre. It was her birthday, "and she's a huge, huge fan. They were incredible," he enthuses. "They're insane. They never play the same show twice. Jack White doesn't know what he's going to play when he goes on stage, there's no set list. It's pretty extraordinary."

This is Elijah Wood: a fan. He knows his stuff. And the stuff he likes, he really likes. Every other Tuesday he and a friend take their iPods f down to LA hang-out The Bar, owned by another friend, and DJ for five hours - it's "a totally random mix of music". He's trying to set up a radio channel for like-minded music nuts on Sirius, a subscription-only satellite service. "People can call up sports radio stations and bitch about sports. Same with talk radio. But as a music fan, one of the most important things is discussion. You bitch about bands, you talk about new records and shows you've seen. And there isn't really a forum for that."

He's in the advanced stages of establishing his own record label, and is currently trying to work out funding for it. He's signed one band, is interested in another two and thinks he'll be involved in "all the creative decisions" with the CDs he puts out. The label is to be called Simian. "I was always called a monkey when I was child. It was a name that my mom gave me, because I'd climb up on to things. And I just love the word Simian." His original choice for the label's name was It's Not You It's Me Records, "but I thought that was a bit 'emo'," he says, referencing the name of the genre of emotionally intensive geek-rock that American college kids are particularly mad for.

How is he going to fit in time for all of this? "Who knows?" he grins through a puff of smoke. "It's ambitious, but it's exciting. And it's nice to put my energy into something else. And I've been so lucky to meet a lot of people in the music industry and be friends with them. So it also feels relatively natural because it's a part of my life anyway."

Unlike his peers in young Hollywood - Leonardo DiCaprio, Tobey Maguire, Ashton Kutcher - living the glitzy LA life is not really this young veteran's bag. Wood lives in the more relaxed area of Venice Beach, remains close to his family, goes to gigs with fellow music-heads, and keeps up with the close mates he made filming the Rings trilogy in New Zealand, including Dominic Monaghan, the Mancunian star of Channel 4's Lost, and the Scottish actor Billy Boyd. The latter had been in Edinburgh just before Wood arrived, promoting the Peter Mullan film On A Clear Day; another missed hook-up that had the American "gutted".

Wood is more fanboy than party boy, and his passions range beyond music. He's a comic buff, and was so into Frank Miller's cult Sin City that he nearly "fell off his seat" when its director Robert Rodriguez - an old pal since they made the high school horror The Faculty - told him he had worked out a way to film the famously dark and fantastical tale. Of course Elijah would like to play the part of Kevin, the cannibal who gets scoffed by his own wolf. Ditto Eternal Sunshine of the Spotless Mind, in which he played a creepy memory-erasing technician: he'd always loved loved loved director Michel Gondry's pop videos, and Charlie Kaufman was the scriptwriting king - you betcha he'd like a part in anything those two mavericks came up with.

Both these post-Lord of the Rings roles - each small but perfectly formed, in eye-popping movies a million miles from Mordor - offered radically different challenges. Likewise Green Street. Rather than him being chased by a director (Lexi Alexander, making her first full feature) in need of a box-office "name" to tee up a small production, Wood pursued Green Street. He was wowed by the at-any-cost enthusiasm to make the film shown by Alexander, a martial arts aficionado who grew up in the German town of Mannheim running with a gang of local football hooligans.

"Lord of the Rings was so massive," he says. "So it was nice to be able to work on something simpler, something more focused, without the grandness and time associated with something so big. Green Street certainly gave me the opportunity to explore darker sides of the human experience which I hadn't really done before. So that was exciting. And I loved the subject matter, I was fascinated with it. It wasn't something, as an American, I was very familiar with." Wood concedes that the journey that Matt takes requires "a lot" of faith on the part of the viewer. Harvard to hooligan is as big a leap as Wood's leap, from the New Zealand-shot Shire to the terraces of Upton Park.

"I think maybe I was a little naive in the beginning, because I just saw it as a character. I didn't look at it in the context of the reality of that world, or how others would perceive an American being involved in that world, until I got to London. Then I realised that the very notion that a Harvard American would fall in with, and become a hooligan, and actually be respected for such, is pretty far fetched. So I tended not to think of it in those terms and just played the character I was meant to play and make that transition as believable as I possibly could in the context of the story."

It's to his credit that Wood makes Matt's change credible. He's by no means a big guy, but when he fixes that piercing stare on the Millwall mob, there's a gravitas and purpose on the screen. He says he relished the challenge to develop a character, and the transformation of their nature into something altogether darker and more complex, without the back-up of prosthetics, computer jiggery-pokery and legions of extravagantly realised extras.

"Frodo was succumbing to an evil. He essentially dies by the end of the [last Rings] film; to strip his soul away throughout the process of the films was a challenge for me. But with Matt, obviously he's making the choice to become this person. That was something that was interesting, to be able to make that change in a subtle way in the context of a human story."

Wood's next film is a journey too, and another left turn. Everything is Illuminated (released in December) is an adaptation of Jonathan Safran Foer's much-garlanded debut novel. Quasi-biographical, multi-layered and multi-textual, the story follows a geeky Jewish-American called Jonathan Safran Foer, played by Wood, as he travels to the Ukraine in an attempt to trace the woman who saved his grandfather from the Nazis. He is accompanied by a translator whose mangled English creates much of the hefty humour. It's been written and directed by the character actor Liev Schreiber.

"It was a wonderful project to work on, and a very different character for me," Wood says. As with Lexi Alexander and Green Street, he was inspired by Schreiber's personal stake and dedication to the story, and rhapsodises about recently watching the latter perform on Broadway in Glengarry Glen Ross.

It is perhaps no coincidence that Wood is also now trying to adapt a book, the cult Russian tome Novel With Cocaine, which features a Holden Caulfield-esque protagonist. He's in the middle of negotiating the rights, might star in it, might produce it. "The idea of developing something from the ground up and ultimately seeing it through to production and finish it as a film is a really exciting concept and, I imagine, very gratifying."

First though, after his Edinburgh premiere, and a London premiere, and no doubt more missed gigs, he was off to France. He's filming a part in Paris, Je T'Aime, a collection of 20 shorts on the subject of love in Paris, directed by a host of different directors including The Coen Brothers and Gus Van Sant. "I feel really honoured just to be part of it."

But no matter where he runs, whatever he does, whoever he plays, the shadow of the Rings won't be far behind. Is that a burden? Wood gives a not-bothered shrug. "It's certainly going to be a part of my life for a long time. I think that was school for life, for all of us. We were all relatively young, and it was like going to university. It had a massive impact on my life. I'm definitely a different person as a result of working on those films. What is truly extraordinary is that thing of travelling all around the world, and no matter where you go, there are fans. And the films mean as much to these people in one place as they do in another country. It's truly extraordinary. But no, it's not a burden, it's something I understand."

Meanwhile, there's the vexed question of The Hobbit. It's still mired in rights hell. But if the film version came together, and Peter Jackson was again directing Tolkien, would he be up for a part? "Probably not," he says with a hesitant wince. Frodo's not in the story, "and I wouldn't want to tackle the role of Bilbo. I went through so much in the journey to play that one character. To go back would do me, and the character of Bilbo, a bit of a disservice. There'd be something sacrilegious about that."

Spoken like a true, obsessive fan.

'Green Street' is out on Friday. 'Everything is Illuminated' follows 9 December