"Is it not enough, these days, to look without touching?" Audience participation terrifies Peter Crawley

You know that anxiety dream, the one where you inexplicably find yourself in a play only to realise that you don't know your lines? Well, I've lived it now. Twice.

Unlike other common anxiety dreams (discovering yourself naked in a public place, failing an exam, the one where your editor shows up at your place demanding Guinness), this distress call from the unconscious now has an unfeasibly high chance of coming true.

The first time it happened was a couple of months ago, when I was hauled from the rear of an auditorium at breakneck speed into the middle of a bawdy Irish-language show by the company Fíbín, joining a cast predominantly made up of fuzzy puppets. It was a bit like being kidnapped by the TG4 version of The Muppet Show.

Recent shows from Gob Squad, Gravity, Ten Directions, Red Bastard, 1927, Rotozaza, Broken Talkers, Dublin Youth Theatre (I could go on) have all provided similar opportunities by encouraging their own stage invasions, rushing the crowd or handing over cameo and starring roles to an unrehearsed Joe Bloggs. It's a phenomenon variously described as "collective creation", "audience participation" or, sometimes, "abduction".

It's not exactly new: any school- kid who's had the wit to shout out "Knock knock!" before the opening line of Hamlet("Who's there?") knows how easily a groundling can make a subversive mark on a classic. And nothing here is as daringly daft as the 1960s experimental anti-illusionism of say, The Living Theatre, whose members regularly got naked with their audiences. Still, I can't remember a time when so many performances invited us through the looking glass.

The most startling thing about Gob Squad's Kitchen, staged recently at Project, wasn't when one of the Squaddies asked if she could kiss the pretty girl she had earlier fished from the audience, but when the girl in question unhesitatingly agreed. Even the actor seemed taken aback. Kitcheneventually replaced every performer with a corresponding audience member, the cast trailing out into the dark auditorium, their substitutes reciting lines from headset prompters.

Is it not enough, these days, to look without touching? Is this tapping into a genuine exhibitionist desire among ticket holders? Do actors and audiences really want to trade places?

Such thoughts didn't cross my mind when I was bundled into the spotlight to play The Gentleman Caller in Bouffon Glass Menajoreea couple of weeks ago. (Surely I qualify for Equity by now?) But this scabrous and knowing parody of Tennessee Williams's classic epitomised that hands-on agenda, involving the audience throughout and ultimately letting its conscript decide the outcome of the show: Guys gets girl.

Whether you find the idea electrifying or terrifying or both, the prospect that you could soon be leaving Row G for centre stage does keep you on the edge of your seat, or clinging to it. The experience is not for everyone or for every play, but when so many people go to a show only to feel frozen out, here's our big chance to get in on the act.