Johnny Depp gets halfway through the sentence before realising that what he's saying might sound a bit odd.

He's telling us about playing with Barbie dolls, not an activity normally associated with Hollywood stars.

But then Depp, who dropped out of school at 15 to pursue a career as a rock musician, has never conformed to the Tinseltown norm in either his public or private life.

At the press call for his new movie, Pirates Of The Caribbean: Dead Man's Chest, he arrives dressed as eccentrically as ever in hat, casual shirt and clutching a takeaway coffee. He's unlikely to be mistaken as Ken, Barbie's constant companion. But he knows Barbie well through his children, Lily-Rose, seven, and four-year-old Jack - his kiddies, as he calls them, by his girlfriend, French singer-actress Vanessa Paradis.

After years of proving his versatility as an actor without ever starring in a gold-plated box-office blockbuster, his talent was finally acknowledged by cinemagoers and critics alike through his performance as Captain Jack Sparrow in Pirates Of The Caribbean three years ago. The quirky character, inspired by Rolling Stones guitarist Keith Richard, even earned him an Oscar nomination - and an action figure to accompany this week's release of the first of two sequels, Dead Man's Chest.

Perhaps Captain Jack and Barbie could get together in the Depp household, where the actor says his kids have had much to do with creating characters like the outrageous pirate.

"The funny thing is, with my kids, when we sit down, play Barbies or whatever, as we all do, you assume characters," he explains. "It's a great way for an actor to experiment with voices, and start to assume a character with a Barbie. My daughter would go, 'pappa, would you do your regular voice?'.

"There was one time when I was trying to find the voice of Willy Wonka and she stopped me and said, 'who's that?'. She liked it. At least, she seemed to. I said, 'I think that might be Willy Wonka', and she said, 'I like that'."

His children haven't seen Pirates 2 yet. "The responsible thing to do was to check it out first before they come to it. I've come to the conclusion they'll be OK," he says.

The popularity of the first Pirates Of The Caribbean came as a surprise. "I'd gotten used to the idea of never having a successful film. I was pretty comfy in that. It was a terrific shock, I'm still babbling over that," he says.

Even acclaimed collaborations with director Tim Burton on movies including Edward Scissorhands and Sleepy Hollow had failed to give Depp a bona fide Hollywood hit. No doubt his dodgy track record at the box-office was one reason behind Disney executives' alarm at seeing early footage of Captain Jack on the original Pirates movie. They suggested toning down his outrageous performance that makes Robert Newton's eye-rolling Long John Silver look restrained.

Public adoration of Captain Jack, the fact that people took to the character and supported him, came as a pleasant surprise. "At a certain point some of the better dressed people at Disney were having a difficult time with my interpretation of the character. The fact that the audience came in and supported me was a win-win situation," says the actor with a degree of satisfaction.

Executives' worries were understandable when you consider Captain Jack's mincing swagger and mangled, effeminate English accent. His body language is all to do with the weather, explains Depp. "It came from extreme heat. I went to a sauna, locked myself in - by the way, I don't recommend that. Out on the open seas for a long period of time, he'd obviously be subjected to the elements. So what happens when you lock yourself in a very hot place? It starts to affect the way you move, that's kind of how Jack's movement was born."

The combination contrives to remind you not only of Keith Richards but also Captain Birds Eye and Julian Clary. The two sequels are being filmed back-to-back, with Depp and the rest of the cast reuniting to complete filming next month.

Refreshingly, Depp rejects any actory character development nonsense regarding his pirate. "I kind of reckon he's fully developed," he says. "He's arrived and had arrived on the first one, so that whole idea of the arc of the character? Bollocks. The guy is, and he sort of moves forward."

What comes across on screen is that Depp's having a ball doing a funny voice and silly walk, and it's difficult to resist warming to Sparrow. For Depp, the role helps fulfil a childhood dream. "I can very clearly remember wanting to be a pirate when I was a kid," he says.

"It feels like that still exists for a lot of people. Something to do with the idea of total freedom. Everybody wants to be that free, everyone would love to be totally irreverent and not have to answer to anyone. He's me and I'm him. He's a character born out of me, but I don't trust him at all."

This success comes at a time when Depp, 43, has settled down. Behind him are the days of one failed teenage marriage, broken engagements, of trashing hotel rooms and fighting with the paparazzi.

The biggest change for him in the past decade has been becoming a father. "But more than changing, I feel like I've been revealed in myself. I've kind of found out who I was," he says.

"That first moment when you meet your child, the first time you're looking at this angel, you start to realise what an idiot you've been for so many years and how much time you've wasted.

"As for being level-headed, or with my feet on the ground, once again my kids and Vanessa have given me proper foundation, a sense of home that I never had in my life, a real sense of family and a place to be."

Pirates 2 is his first sequel and he's happy to keep splicing the mainbrace for as long as audiences want to see Captain Jack. Producer Jerry Bruckheimer has said that he's looking to make more Pirates movies beyond number three. "As long as there's a good script there, you're OK," says Depp.

"I'd be happy to keep going. I just very selfishly enjoy playing the character. I really love playing the guy, purely because it's fun, nothing more.

"There's no evil moment when you go into a back room and start counting money. It's never been about that for me. It's purely about playing the character. So if these guys want to continue on the same ride, if everything's in the right place, if the script and story were good, I'd stay on the ride, sure."

He admits to missing characters once the cameras stop turning. "It sounds horribly silly for a middle-aged man to admit, I do maybe go through a bizarre deep depression and you miss these guys because you know you're never going to see them again in that capacity," he says.

"I'm not looking forward to saying goodbye to Jack Sparrow."

He can look forward to one piece of Pirates 3 casting as producers are hopeful that Keith Richard will play a cameo role as Captain Jack's father. "It's looking good. The one thing is you just never know it's definite until the guy steps on set," he adds.

Pirates Of The Caribbean: Dead Man's Chest (12A) is now showing in cinemas.