Sarah Vowell: Superheroine!

I met Sarah Vowell eight years ago, on my first American book tour. She wanted to talk to me about a piece she was making for the wonderful NPR radio show This American Life, and initially I couldn't concentrate because I was distracted by her voice: it had this drawly, Boopy, Lisa Simpsonesque quality that made her sound a good decade younger than she looked. But as I didn't know how old she was, and didn't like to ask, I spent the first few minutes of our interview wondering whether the funding crisis that afflicts public service broadcasting in the US meant that high-school swots could get high-profile radio jobs.

In other words: within five minutes of meeting her, I was pretty confident that one day Sarah would get cast in a huge Pixar film as a teenage superhero. I was even going to have a bet on it. Honestly. I can't remember now what stopped me. Looking at the blurbs on the back of Sarah's first book, published in 2000, I now see that most of her friends and admirers knew this was coming. Lawrence Weschler described her as "equal parts Betty Boop and Dorothy Parker", while Steve Erickson - and this is spooky - decided that she was "original, funny, bracing, pixilated". Sarah Vowell has clearly always been a cartoon waiting to happen.

Anyway, at the end of our interview she gave me a copy of her first book, Radio On, and once I'd read her prose, I stopped thinking about her speaking voice. We don't have anyone quite like her here, and we're the poorer for it. Her two terrific collections of essays, Take The Cannoli: Stories from the New World and The Partly Cloudy Patriot, are funny, sweet, smart and soulful, and evince a fascination with, and a devotion to, all things American that might deter some readers of this newspaper at this point in history. Vowell would understand - she's a democrat in every sense of the word - but if you do decide you know enough about the kinder, gentler America, and you need a guide to the apparently unfathomable mysteries of W's country, then Vowell's your gal.

She grew up in Oklahoma and Montana, and she went to a Pentecostal church when she was a kid, and her dad is a subscriber to Guns and Ammo magazine. Her prose has a twang that we rarely get to hear, not least because we're usually too frightened to listen. There's nothing to be frightened of here, though. Whether she's writing about Al Gore as nerd, the Gettysburg Address, the cannon her father made or presidential libraries, Sarah Vowell has a charm, a wit, a sanity and a good humour that will stop you worrying quite so much about the future of the world.

In New York earlier this year, she made me sit for an uncomfortably long time in Gramercy Park, looking at a statue of John Wilkes Booth's brother, while she gave me a lecture on the Booth family. (The Booths were like the Baldwins, a big, respectable acting family, so John shooting Lincoln, like that was really embarrassing for them.) Earlier on, we'd been talking about The Incredibles, and how there were going to be all sorts of Violet Incredible toys, and you'd be able to press a button in a Disney store somewhere and hear her voice. I wish someone had been sitting with me recording her impromptu Booth lecture, so that they could have used it for the toys; it would have been entirely appropriate somehow.

So, Violet Incredible. How's your political-assassination book shaping up?

Finished! The publication date is April. It's the story of the assassinations of Abraham Lincoln, James A Garfield and William McKinley - and tourism. The title's Assassination Vacation. So I tell the story of the first three American presidential murders by going places and looking at what's left behind, ie museums, tombs, old houses, highway historical markers, monuments and plaques. Plaques get a ton of play.

Today is a particularly exciting date in that in about half an hour I'm taking the train to Philadelphia to give the keynote address at a convention of museum employees from the Atlantic region. Fun! I can't wait to read to them my analysis of the display of Lincoln's skull fragments from DC's National Museum of Health and Medicine.

They asked me to speak because I write a lot about museums, which I hadn't really noticed before. I think I write about museums a lot not so much because I like to look at old dusty things under glass but because I'm not so good with living things. I used to be more of a proper reporter, but I'm terrible at it because I don't like to pry. I'm polite and nice. This is a major flaw for an interviewer. I like writing about dead people and dead presidents in particular because of the distance. It's the major reason I don't write about JFK in this book. That wound's still fresh. The nice thing about President Garfield is that people are over his death.

I hope the book comes out with a movie tie-in jacket.

That's a good idea. Violet will throw a force field around Lincoln so John Wilkes Booth's bullet bounces off.

So did this really come out of the blue? Someone phoned you up and asked you to be a Pixar character?

Fairly blue. Light blue. I do get weird offers and queries from TV and movie producers from time to time. If you're mildly entertaining on the radio or in books, Hollywood does come calling, but nothing's ever worked out for me. I've had my share of uncomfortable if delicious free lunches in which well-meaning producers look at me with a combination of pity and disbelief when I say I actually just like sitting by myself in my apartment writing books, books which can never be turned into movies because every few pages I interview a museum docent and/or park ranger. Not that I wouldn't love to see Meg Ryan standing in the Lyndon Johnson Presidential Library having an epiphany involving the Vietnam War, the Voting Rights Act of 1965, and "Louie Louie", because I always like her hair.

Anyway, Pixar. What happened was, Brad Bird, the director, had the radio on while he was thinking about casting. There's this radio documentary I made for a show here called This American Life about a cannon my dad built from scratch and my dad and I driving up into the mountains to shoot it off. The cannon is crazy loud and smoke comes out of it like in a cartoon and I said so on the air. Brad heard that and thought I could be Violet. (Violet is a little smart-alecky and also has a weird dad with a strange hobby).

One thing they do at Pixar when they're casting actors is that they take the voice tracks off actors in movies or television shows and do test animations to their voices. I guess because some actors' power is exceedingly visual. Apparently not every actor comes across. I've seen the test animation they did to that cannon documentary. It's funny. It's Violet in her superhero suit holding a huge gun that keeps going off and scaring her.

Then I got an email from the producer. It was just the sort of left-field - that's a baseball term, so insert some crickety British phrase if you'd like when you go back and start putting a bunch of extra letter U's in my words - offer I turn down without blinking. But it was from Pixar. They're the best at what they do, the most universally culturally revered. It's like if Nelson Mandela showed up asking for your help to fight racism. Maybe fighting racism isn't normally your thing. Maybe you're more of an armchair racism hater. But if Mandela was standing at your door asking you to get on the bus, you'd just start putting on your shoes, right?

Plus, coincidentally, the day before I got that first email from Pixar, I heard a radio interview with the studio's founder John Lasseter. He was talking about Monsters, Inc. and how since the monster corporation was fueled by the screams of children, they decided the corporation would have expanded not long after the baby boom boomed. So corporate headquarters would probably reflect that architecturally. That's why the building has that late Fifties, early Sixties Mies van der Rohe look. Now, what five-year-old is going to pick up on that Mies reference?

They made such decisions to amuse themselves, but also with the hope that extra meaning could be communicated on a more subliminal level. That's why I said yes to entertaining the thought of acting, of doing something I had never done before. I was hoping some of Pixar's storytelling mojo would rub off on me.

So was it like doing radio work? Were you in a room, on your own?

Same sort of sound studios, but with radio, I'm always in a studio by myself and sitting down and for the movie I was always in the room with Brad the director and standing up. There's more gesticulating.

Also, once I had to record the ocean scene. I did that one at the Pixar studio in the Bay Area. The first thing I saw when I went in there was a stack of towels and a bunch of water bottles. I had to gurgle and gulp and sound like I was almost drowning. The towels worked as bibs but I still got a little soaked. I feared I might be electrocuted what with spilling and spitting all that water near so much electrical equipment. Also different: nonverbal sounds.

Have you ever had to giggle, yawn, scream, sigh, guffaw on command?

That was actually the hardest part of the job and something my radio essays and documentaries hadn't prepared me for. At the first session I was supposed to make a sound into the microphone like I had just been punched. Like, "Uh!". I was having trouble, not being an actor, and finally I just told Brad, "You're going to have to hit me." So he stood next to me and punched me in the arm. We always recorded the screams at the very end because they wreck the voice. That was super fun. I don't think I had screamed, really screamed, for about 20 years.

When did you first see Violet? What did they tell you about her? Did you see any visual stuff at all when you were doing the voice?

There's this one drawing they showed me very early on that was actually the deciding factor in me saying yes to giving this a go. It was a line-up of Violet's fellow students at her junior high school. They're all these smiling, shiny, happy, well-adjusted and outgoing-looking adolescents except for this one girl in the middle: Violet. She's wearing dark baggy clothes and she's hunched a little, hiding behind her hair. I thought, That kid? I can be that kid. I was that kid. I love that archetype of the morose, shy, smart-alecky teenage girl.

One of my nicknames used to be Wednesday, as in Addams. And Violet's powers, like the other members of the Parr family, are psychologically representational of who she is. Her powers are force fields and invisibility. And that's so teenage girl of her: wanting to hide, wanting to protect herself. Her little brother's power is that he's extremely fast; he's a blur: an amped up, all-over-the-place, hyperactive little boy. And her mother's power is that she's stretchy, just like a mom pulled in a million directions by the demands of her family.

Did you ever meet any of the other actors, or were you always on your own?

I met Holly Hunter a couple of times. She's my mom - my tiny, Oscar-winning mom. And I had a session at Disney in LA once that coincided with my dad, Craig T Nelson. I had just been to the Oneida Community (researching the Garfield assassin, who lived there). It was this 19th-century biblical sex cult in Upstate New York. And Craig had once made a documentary on their nearby, quasi-Christian though abstinate neighbours, the Shakers. So we had a kind of involved conversation about 19th-century religious communes. And I met Samuel L Jackson at the premiere. I think I couldn't think of much more to say to him than, "Wow, you're Samuel L. Jackson!" He plays Frozone and his power is making ice. You know, because he's soooooo cool.

The person I was most excited to meet wasn't a fellow actor, but Michael Giacchino, the composer of the score. I'm so crazy about the music in this film. The textures and moods and sheer blasty fun he came up with! That guy knows how to mute a trumpet.

And he does the music for this new TV show Lost I'm sort of obsessed with. I don't know if you get it in England but it's about these plane crash survivors on an island somewhere. It's super creepy and his music is almost a character it's so psychologically tense. I can't eat when I'm watching it because whatever he's doing with his string section sort of turns my stomach - in a good way.

And also: do you understand any of the process by which they make this stuff? I remember you telling me some weird glitch with things sinking through surfaces...

Yeah, the technological demands of this film were stupefying. The computers had to be taught. Like they had to be taught that when you place a stapler on a desk it stays on the desktop instead of sinking into the wood. Apparently, the most gripping brain-teaser was Violet's hair. Organic things, especially organic things that move, are exceedingly difficult to animate. Violet has very long hair. For most of the process, and in many of the rough cuts, Violet is bald. John the producer kept going up to the cave where the hair animators lurked begging them to give her hair and they would break it to him that "the hair is still theoretical." But do I understand how the hair moved from theoretical to actual? No way. There's a reason the end credits on this movie are so long.

Speaking of which, my favourite part of the credits is the list of babies at the end. Because the movie took four years to make, and it took so many people to make it, an entire generation of children were born to the Pixar employees. I love that all those kids' names are listed. How great will that be when they're a little older and can see their own names in the credits? The other night I met a little girl who was planning to dress up as Violet for Halloween. That's not the sort of thing that happens to a non-fiction writer.

'The Incredibles' (U) is released on Friday. 'Take The Cannoli: Stories from the New World', £7.99, and 'The Partly Cloudy Patriot', £10.99, are both published by Penguin