It's midway through a jam-packed Toronto press junket, Chris Martin and Johnny Buckland have been holed up in the same hotel suite talking to reporters for hours, and they're on the final question of one of their last interviews of the day. Asked if it's been healthy for Coldplay to become so big, so quickly, they could easily serve up a quick sentence or two and usher in the next scribe, already waiting at the door.

That, however, is not the way the most eager-to-please Englishmen ever to be branded the next biggest band in the world go about things.

"Life is so short," Martin begins, "we've gotta pack it all in. For all we know, we could be living in a Mad Max world in three years."

Or, his guitarist offers, the band could be playing on a cruise ship - which, the singer points out, might not be so bad. Inevitably, they wind up on the subject of playing a cruise ship during the apocalypse - and when it's suggested this could make for a good concept album, Martin takes the ball and runs with it.

"Well in fact, you're talking about our musical coming out next year, called Cruise Ship of the Apocalypse," he deadpans. "And I think that's going to be our biggest album yet."

The next thing we know, the sharp-eyed singer is rhyming off lyrics (The captain says we're sinking/But I don't know what he's thinking/Maybe he's been drinking) as Buckland cracks up. And even when he stumbles on the second verse ("The steward says we're floating ... ah, forget it"), and their publicist is anxiously waiting to get the next behind-schedule interview in the door, he seems like he could keep going for hours.

"I'm just obsessed with this idea," he says with a grin, then warmly bids adieu looking as though there's nothing he'd like better than to keep making up goofy lyrics for a journalist he's just met.

Heading out the door, it's impossible to remember coming in expecting to be irritated.

***

There is much to dislike about Coldplay in general, and its take-charge frontman in particular.

They are unabashedly eager for commercial success. In advance of next week's release of X&Y, their third album, they're literally everywhere - every TV show, every magazine cover, every playlist. They've inspired a whole wave of lesser bands to imitate their brand of piano-pop. Martin is married to one of the world's biggest movie stars, and has a child named Apple. And so on.

The thing is, though, that's all on paper. In the flesh, they're so endearing that it becomes clear their rapid ascent - from an amiable but hardly earth-shattering hit single, 2000's Yellow, to challenging U2 - has as much to do with their charm as their creative output.

That's not to say they haven't got the music part down pat. Each of their three albums has built upon the last, maintaining the basic formula while upping the ante with increasingly massive hooks, choruses and production quality.

And while X&Y could be criticized for laying it on a little heavy - each song starts slow and stripped-down, then rises to a cacaphony of keyboards and soaring guitar chords amid ambitious meaning-of-life lyrics - the fact that virtually every track could be released as a single means it's going to be sitting high on the charts for an eternity.

For all the consistency in Coldplay's sound, both the music and the winning personas are the product of a band with a distinctly split personality.

"There's one side of us that really believes we're the best, and works very hard to try and prove that," Martin says. "There's another side that always feels the need to validate these incredible jobs that we've got.

"We've got a new album so we're essentially a new band again, and we have to prove ourselves all over again. So we're terrified in one sense, but really excited in the other."

That combination of doubt and self-assurance is presumably what made the recording of X&Y such a famously drawn-out process, spanning 18 months and a lot of rewrites. But Martin and Buckland insist they went from a counterproductive sort of pressure to a much healthier kind.

"Initially we were responding to the external pressures, having sold a lot of records and being the flagship for EMI or whatever," Martin recalls. "And that really did absolutely nothing for us creatively.

"Then, accidentally really, we ended up in a tiny rehearsal room in North London playing the four of us together. And we loved it, and couldn't understand why we hadn't done that for all those months previous. Once we rediscovered that, we realized that the main pressure really came from ourselves in trying to excite each other ... and that was the best pressure to respond to."

Still, it's hard to remember an act this big being so concerned with what others think.

By Martin's account, they spent at least three or four months while X&Y was still in production playing it to outsiders. In part, they say, that was simply so they could gauge how comfortable they felt letting others hear it. But "just by other people's reaction as well," Buckland attests, "you work out what you think of it." In the same vein, they acknowledge that reading their own reviews helps them analyze what's working and what's not.

It's a method that wouldn't work well for a band unconcerned with pleasing the masses. (It's hard to imagine Radiohead, to whom Coldplay initially drew copious comparisons, changing their albums based on listener feedback.) But at its heart, Coldplay is a quintessentially populist band.

We're supposed to root for people like them to fail. But they want so badly to be liked - and work so hard at it - that fans and critics alike wind up rooting for them to succeed. With that kind of goodwill, there's little danger of having to play a cruise ship anytime soon.