Four years ago, bumping into Howie B was easy. In Dublin to work on an album with Irish rappers Scary Eire, he became a familiar night-time figure around Temple Bar, a cheery Scot charming all with that infectious grin as he scamped from one underground club to another. Four years on, bumping into Howie B is altogether more difficult. He's on the road with U2 in Europe, so there's a week of telephone tennis before Howie makes that call. He's waking up in Vienna: "Vienna is Vienna; you know, loads of sausages."

These days, Howie B is a busy man. Not only are there U2 commitments - DJ-ing before they come on, overseeing the sound when they're on stage and providing the vibe to go with that lemon - and his Pussyfoot label to marshall, but he also has one of the albums of the year to promote. Turn The Dark Off is his second album, a fresh and cheekily innovative collection of warped beats and twisted melodies. Containing a blueprint for 21st-century dance music, it shows clearly that Howie B is as diverse an artist as they come. For many, though, Howie B is still the U2 supersub, the man they brought in to add his eclectic something to the mix and to give them a kick up the arse in the process. The association has continued into their live engagements with Howie on hand to provide some fierce pre-set tunes. Stadium DJ-ing, however, is not always a bowl of cherries. "Warsaw. I had a funny time there. I normally play for about 45 minutes, but because there was a problem at the gates, there was still a lot of people coming in to the gig. I had to play another 45minute set. The crowd didn't particularly like that. I was getting vegetables, pieces of fruit, cans, bottles, cups thrown at me. "Before the gig, I had been warned that there was tons of mosquitoes around the stage so I sprayed myself all over. About an hour into it, I felt this big bite on my shoulder. I was, like, what the fuck, that's one massive mosquito. Then another bang, then another bang and I suddenly realised it was apples and cabbages not mosquitoes. That crowd didn't want me, they wanted U2."

Shennanigans with mafia types at his post-U2 club gig, not to mention his record company booking him into a youth hostel pretty much ensures that Warsaw is not the city Howie will remember most from this adventure. "It was a one-off. Prague; Prague was beautiful, a magical place. And Rotterdam, Brussels. The difference between Europe and the States is that at least two-thirds of the audience are standing. In the States, we were playing all-seater venues. Here, because it's big stadiums or big fields, the audiences are actually standing up so I'm playing more up-tempo stufff. Hiphop, old jazz, big beat, little bit of techno, some Pussyfoot vibes".

His work doesn't end when U2 take to the stage. "I'm also doing the U2 sound. It's hardcore! I've got this massive desk and the full system as an instrument. I'm pushing it as far as it will go. I'm delaying stuff, dubbing stuff, cutting the drums out here and there, messing with the guitars; it's getting quite mad, to be honest."

That workload would be enough for many but Howie also has his Turn The Dark Off agenda. Whereas Music For Babies, the debut album, was a gorgeous ambient affair, Turn The Dark Off provides beats in spades. "People were dissing Music For Babies because it didn't have any beats - like, how narrow-minded can you get? You try to ignore some of the things you hear but some do stick. Turn The Dark Off is my way of saying `listen, I can turn it on with the beats vibe, there you go'. It was a bit of a challenge as well because there is a lot of beat-orientated stuff around at the time. It was also a throwdown to certain people.

"But I'm not just chucking beats in for the sake of it. Each beat is doing something or not doing something, each sound is there for a reason, they're all shaking hands with one another. It's definitely a Howie B thing. What I love doing is shocking, whether it is with humour or sound or just doing the unexpected. I knew it would freak them all out; they wouldn't know where I was coming from and, even better, they wouldn't know where I was going."

There's quite an aggressive undertow running through the album, from the skank-fried Butt Meat to the full-on Angels Go Bald Too. Howie puts this down to circumstances. "There's a lot of what was going on in my life at the time in there. I had just finished working on the Pop album, I had gone back to London, lots of things had finished, lots of things were about to start up, I had come out of a relationship with someone and I was getting into another one, lots of stuff going down.

"Turn The Dark Off was the platform I used to get it all out. I actually thought there would be more aggression in it. I was going to call it Aggressive Behaviour at one point, but it doesn't really warrant that title. Maybe when I'm 76, I'll make a really aggressive album - but this one is me telling myself to get my shit together and stop walking around with my head down."

One of the standout tracks on the album is Take Your Partner By The Hand featuring Robbie Robertson. "It's about how dance is about communication and no communication, how two people from opposite ends of the world can come together and dance and not need to have to say one word to have a totally outrageous time. I had the track already done when I went into studio with Robbie and decided it would be mad to get him to talk or sing over it. He went away for two days, came back and gave me the tune. He just got everything down to a T. Crazy!"

Besides musicians, there are also ongoing collaborations with writer Mike Benson and animator Run Wrake. "I'm starting up a book publishing company, Pussyfoot Press. The idea is to put fiction where it has never been put before. You get liner notes on a record and they're boring so, OK, let's put some fiction in there. You should be able to use that space on the packaging to squeeze in another piece of art. Mike Benson's text (which has appeared on both album sleeves) stands alone from my music yet it also works with it, the same with Run Wrake's animation."

The next couple of months are already well mapped out on the Howie B wall-planner. "I have to finish this bit of the tour, do the next American leg, promote my album out there, go to Cuba, do something there - what, I don't know, maybe a cigar-rolling course. After that there's a wee album to do with Bjork, then another little project for myself. Then who knows? I've had a few calls from Texas about doing stuff. Madonna has called."

For Howie, these projects mean one thing. "I keep bumping into people. It's a natural process. I do the things that people who love music do - I go to clubs, I buy records, I talk about music, I meet people who make music. I've never gone fishing. If I meet someone who wants to make music with me and there's a vibe, off we go. It's the best way for me to operate. Chance and chaos, that's me."

Howie B's Turn The Dark Off is out now on Polydor.