I saw a very funny clip the other day of Iggy Pop doing a version of Madonna's Ray of Light at the Rock and Roll Hall of Fame. All was going swimmingly until he jumped into the audience and started bellowing in the faces of the front row. Which would have been fine if this was your normal gig, but these people were mostly middle-aged (albeit younger than the Igster) and wearing tuxedos and dickie-bows. Their responses were a mix of boredom and sheer fear.

As a comedy fan I could relate to this. Some of my most excruciating experiences have been at comedy gigs where the performer has broken down the fourth wall and strolled into the crowd. As a notebook-brandishing critic I always dread that moment when one of them spies my pen and paper. So far I've been lucky, but there have been some close shaves. Madcap Irishman Jason Byrne once saw another critic in the crowd and said that he should make notes on his scrotum as it would be more discreet than using a notebook.

At Little Britain's Hammersmith Apollo show Matt Lucas paused right by me when he was dressed as Marjorie Dawes and looking for someone to weigh onstage as part of his Fat Fighters sketch. Fortunately I wasn't fat enough. In Croydon last autumn Russell Brand stood so close to me while eyeing up potential sexual conquests he almost garrotted me with his microphone lead. Luckily I'm not his type.

Stewart Lee took a more kind, considered approach, strolling up the aisle at the Soho Theatre without picking on anyone at all. Unlike spoof trolley dolly Pam Ann, who hurtled up and down the steps looking for someone to drag onstage. Pam, as always, managed to scare the beejesus out of me without actually coming within five feet.

Sometimes, of course, stepping into the audience can make a fan's day and maybe even make a show. In Phil Nichol's if.comedy-winning set Naked Racist he roamed through the audience completely nude to rapturous applase from everyone. I even clapped myself, but then I was safely on the far side of the room. I'm not saying that it helped him to win the award, but it certainly showed that he had something every successful comedian needs. Balls, in every sense of the word. Maybe I should have made my notes on them.