The 20th-century enthusiasts in the standing pit at Shakespeare's Globe may be short on cutpurses, conycatchers and destitutes
My taxi driver's sons, it turns out, are the proud owners of two of the flagstones around the Globe Theatre. He bought them, at a cost of pounds 300 each, to commemorate the boys' births. The money helped build the Globe, and the names will remain until they are worn away by the scuffing of a million theatre-goers. "What's it like?" he asks, as we swing through the alleyways of Southwark. "We keep meaning to go along, but we've never quite got round to it. I keep hearing it's terrific, though."

This is the joy of Shakespeare's Globe: in its way, it is more a people's theatre than any council-subsidised workshop. Those who contributed to its reconstruction are as much taxi-drivers as the usual run of charitable donors. Even the most grudging theatre-goer exudes enthusiasm after a visit. In this, its first season, the Globe Theatre Company is doing two plays - Shakespeare's Henry V, starring Mark Rylance, who is also the theatre's artistic director, and The Winter's Tale. From next week until the season ends on 21 September, playgoers will also get a choice of two more - Thomas Middleton's A Maid's Tragedy and Beaumont and Fletcher's A Chaste Maid in Cheapside.

The theatrical experience lies as much in the standing pit audience, the groundlings - in their participation, confusion, tears and cheers - as it does on the stage. This place is anecdote central: the American who was heard to say "It's OK, I guess, but I'm sure there's a replica of this back in the States"; the French playgoers who bombarded the cast of the sterlingly Francophobe Henry V with cabbages.

Mingling with the groundlings in the pit before a performance, I stand beside two east-coasters who have bumped into each other far from home. "What do you think?" he asks. "It's certainly different," she replies. "Mmm," he agrees. "We were here three weeks ago, sitting up in the gallery. It was very nice, but people kept catcalling and stuff. It's hard to get used to." "It's a strange way of going about theatre," she says. "Oh, I gather it's pretty authentic." She muses on this. "Well, you sure surprise me."

Authenticity, of course, is always relative. Although the punters obviously relish the freedom to wander, English wine and snack in hand, the pit is noticeably short of cutpurses, conycatchers, prostitutes and garlic- chewing, fleabitten destitutes. A smattering of enthusiasts occasionally attend dressed, Rocky Horror-style, in Tudor costume. But sartorial style below the stage, where every incoming playgoer wanders up and fondles the straw to check its authenticity, tends more toward jumpers than jerkins.

Social divisions are still marked: theatre-lovers downstairs, shouting, whistling and interacting; corporate suits lounging in the "Gentlemen's Rooms" above, looking as much at each other as at the action. Their popping champagne corks cause regular waves of hilarity among the groundlings.

Groundlings behave more like pantomime or rock audiences than witnesses of high art: they hiss villains, cheer heroes, wolf-whistle the cross- dressed female parts, shout out comments: "We're with yer, Harry!" - "Go on, snog 'er!" Reflective moments, soliloquies, tragedies, make couples adopt the time-honoured festival slow-dance behaviour: she in front, he behind with his arms round her neck and torso, swaying. PDA is the order of the day. Mark Rylance addresses the "England, Harry and St George" speech in Henry V directly to the audience, as though they are his own massing troops, and they respond by stamping, cheering and punching the air.

One would never see this in the usual, sedentary theatre audience: no one believes that they are about to run off into battle when they are sitting in the dark on plush velvet with a tub of Haagen-Dasz in their lap.

When Rylance exits, sword waving, you expect the audience to pour onstage and follow suit.

During intervals, once the water sprayed on the auditorium floor has evaporated, people sit in cross-legged knots and gossip about what they've seen. Some teenagers discuss the unmasking of the traitors Scroop, Cambridge and Grey: "," says a boy, "they were girls or something. Going, like, 'kiss me on the lips' to this guy'." "Well," replies a girl, with the authority of female intuition, "if you were about to be executed, which would you rather? That, or he spit in your face?"

Two little girls in Spice T-shirts dance from foot to foot. "It's cool, isn't it?" "Really cool. Isn't it cool?" "Yer, really".

Of course, you can't please everyone. A group of Sloanes - 22 and practising to be their mothers, hair bleached and coiffed to concrete - have stood stonily for an hour and a half. "It's sooo vulgar," says a young woman whose idea of good taste is radically ironed striped shirts and cabochon paste earrings. They continue to not laugh until act four, when Rylance, back to the audience, falls to his knees to deliver the pre-battle soliloquy. Silence grips the crowd, and hairs stand up on backs of necks as though a wind has blown through the amphitheatre. The Sloanes, at the sight of his velvet-clad backside, nudge each other and snigger, holding their noses and snorting round their fingers. One person's vulgarity, it seems, is another's high drama

Shakespeare's Globe, New Globe Walk, Bankside, London SE1 (0171-401 9919)

Dressing the part: when you are standing in the open for three- and-a-half hours it pays to wear appropriate clothes