Because this week and next I'm presenting Radio 4's The Film Programme (Fridays, 4.30pm), I've been back on the interview trail. I like it. I don't consider myself the world's greatest interviewer, but I do my research, I don't read my questions off a piece of paper and I attempt, usually in a limited timeslot, to ask something original. Last Monday I interviewed Ken Loach. This was a life's ambition. We sat for just over an hour in his Soho office and covered as much as we could from his 40-year career. At 71, and still working hard, he had a real twinkle in his eye, and even though he's dead serious about his filmmaking and his politics, he was anything but dour or hectoring. That interview will air in next week's programme (August 31). Then, on Wednesday, I interviewed the 81-year-old Albert Maysles (which I've never been able to pronounce, but it's "Maizles"), who, along with his brother David, made two of the greatest rock documentaries of all time, What's Happening (since expanded to become The Beatles' First US Visit for DVD) and Gimme Shelter. Mr Maysles was in his home in New York, I was in London, but it was still a pleasure to hear his thoughts. This is for a forthcoming Radio 4 documentary on Rockumentaries. More details nearer the time. Then, on Friday, I met John Waters, also a man of advancing years at 61, at the National Film Theatre, to talk about his one-man show, now captured on film as This Filthy World, which is not released until November here, but is a hoot. He was as I'd hoped he would be: camp, larger-than-life, all the cliches. This interview plays out today, but as with about six months' worth of Film Programmes, stays up on the website for ages, and not just for a stingy week. That was last week.

This week, I interviewed Chris Cooper, the doughty character actor, 55, who's finally landed a mainstream studio lead in the excellent Breach, released next Friday. This interview, in which I was able to tell him that Matewan, the 1987 John Sayles movie about unionisation in the mining industry in the 1920s and Cooper's first film role of note, "stirs my blood", airs in today's Film Programme at 4.30. You will also hear me talking to Judd Apatow, 39-year-old writer, director and producer of Knocked Up, released today, having made over 150 million dollars in the States.

I think Knocked Up is a revelation. I don't usually like comedies aimed at young men (ie. the Frat Pack movies, the Pie franchise, even the latter Farrelly movies), but this is a cut above. Apatow's The 40 Year Old Virgin showed a sensitivity unusual to the genre, and the supporting cast, including Seth Rogen, Leslie Mann and Paul Rudd, who star in Knocked Up, were exceptionally funny. What's clever about the new one is that it's about, as I'm sure you've read, an unwanted pregnancy. Not the sort of issue usually covered in slacker comedies. It's as if Bluto in Animal House was forced to face up to his responsibilities, which would have ruined that film in 1978, but makes this one a real cornerstone in 2007. There are set pieces and gross-out moments, but these are countered by serious discussions about what parenthood and marriage mean. It's been called "conservative" and I guess it is, in that it promotes marriage and family, but it doesn't necessarily attack the alternative pothead lifestyle lived by Seth and his Geek Chorus (which includes Jonah Hill, who stars in the forthcoming, Apatow-produced Superbad and could be the new Chris Farley, except hopefully with a longer life ... and better films). I'd recommend you go and see it. Apatow is rare in that he can write for women (his wife is Leslie Mann, and she's in it, so perhaps she gives him tips on how women think and talk), and for every instance of a slacker hi-jink, there's a short, sharp shock of responsibility for Seth.

Because of doing these radio programmes, and filling in for Mark Kermode on Five Live today (3pm) and News 24 next Friday (5.45), I've also seen pretty much all the films released this and next Friday. I can't review them all. You'd get bored. Anyway, the upshot is, I've really enjoyed meeting and talking to these talented film folk, young and old. I hope you enjoy the edited interviews when they go out. I'll be the one who doesn't sound like Mark Steel.