Where do you think 'Half-Blood Prince' makes the biggest departure from earlier Harry Potter movies?
I think it's in the comedy. We really go all out on the comedy this time. It's a very funny film, there are some really funny moments in it. And there are more drug references in this film than there have been [laughs]. It's very strange trying to explain them to people sometimes. Also, I think in terms of Harry's character, individually, before he's always been Dumbledore's student, whereas here he becomes Dumbledore's lieutenant. In this one he's a fighter. He's starting on the path to becoming the warrior that he is in part 7.

How has the dynamic changed for you, Rupert Grint and Emma Watson on set, going from child actors to adult stars?
It's been great, actually. But what's great is that the people we work with, in terms of the crew, have seen us when we were kids as well, and so I think it's been interesting for them to see the journey of starting to take it seriously and going from being kids who were having a great time on a film set to suddenly really wanting to do this for a living, which me and Rupert certainly do. I think Emma does as well, though she's going to study for a few years as well. I think that's the main difference, is that I take it much more seriously. The more seriously you take it, the more fun it becomes. It's a very, very rewarding profession when you feel that you're getting better at it. I feel like I've made a big jump since the sixth film, I got better since finishing the sixth film, doing 'Equus' on Broadway, and now doing 'Harry Potter 7.'

How do you feel about Dumbledore becoming somewhat of an icon for the gay rights movement?
It's wonderful. I grew up around gay people my entire life, basically, that's possibly why I'm quite camp, and some people think I'm gay when I meet them, which I think is awesome. It's always good to keep them guessing [laughs]. I don't go on any blogs or chats or anything, but my friends are demons for them, and apparently someone said "Daniel Radcliffe is gay. He's got a gay face!" [Laughs] I really don't know what a gay face is. But I think it's wonderful that Dumbledore was outed as gay ... Half of me thinks Jo Rowling just did that to see if she could [expletive] off the right wing, but I'm not sure how true that is. I think she had it planned, I think she always knew he was gay.

Was 'Equus' a strategic move in terms of your career path and trying to break away from the 'Potter' pigeonhole?
I don't like to say "strategic," because it makes it sound very cynical, the way I'm planning my career, very Machavellian or Mr. Burns. But we knew we needed to do something different, and we knew that if we were going to do something on stage, it has to be something that would say, "I'm doing this seriously. I'm not just going to do a light, fluffy piece on stage, I'm going to do something serious that will make people go, 'OK, he wants to take this seriously, and he wants to work hard.'" That was certainly one of the reasons behind doing it, but also just to do 'Equus' was amazing. And when you think about it, there are very few decent-sized parts for 17-year-olds in stage, generally speaking.

Has it been odd to watch not only yourself, but also Rupert and Emma go from child star to sex symbol?
It's been funny with Emma. Yeah, it's been very strange to watch that suddenly happen, because there was that weird time when she was like 15 or 16, and guys kind of knew they fancied her, but no one could say anything. She's always been a very, very pretty girl, and now suddenly that she turned 18, everyone's like "OK, now she's fair game! Paparazzi!" It is kind of creepy, I did feel bad for her. Men will never know the kind of humiliation of having an upskirt done, which poor old Emma had. We talked a few days after her birthday, and she said, "It was awful, they were all over me. They were trying to shoot up my knickers!" It's incredibly invasive. That's why I do think it's much, much harder for girls being famous than it is for guys.

If 20 years from now J.K. Rowling revisits the 'Potter' kids as adult wizards, would you imagine doing the movie?
I saw her the other day, and I said, "You're not writing any more ['Potter' books], are you?" And she said, "No," and I said, "OK, cool." And then I said, "You know, if you did, I would have to think long and hard." I think also I would only do it if Emma and Rupert would. Honestly, after the seventh film, I don't think she should do anymore. I think it would have to be something pretty good. But Jo Rowling's such an intelligent person, she knows. She knows if she was ever going to consider doing another, it would have to be bulletproof. It would have to be an almost perfect book not to get slaughtered. So hopefully she won't, but if she does, of course I would have to consider it, because I have a loyalty to her and to the fans. But it certainly would not be in an instant.