I don't know whether Spalding Gray's "Swimming to Cambodia, Part I" qualifies technically as theater or just lively talk. Maybe we should call it lively talk in a theater and leave it at that.

Whatever it is, this 1 1/2-hour monologue, the first of six that Gray will be delivering over the next four weeks at the New Playwrights' Theatre, is uniquely absorbing as it winds its way over the hills and dales of the performer's life and through the gullies and caves of his mind. If at first you have the sinking sensation that you are being pinned to the wall by an especially loquacious barfly, just hold on. The more Gray talks, the more compelling he becomes. By the end, he has ushered you through a world. Worlds, in fact.

"Swimming to Cambodia" takes as its point of departure the performer's experiences in Thailand, where he spent eight weeks on location for "The Killing Fields" (he played the American ambassador's aide). Eight days were devoted to working -- the rest, one gathers, to looking around. Not only looking around, but trying to force his observations into a pattern, make sense of them, knit them into the fabric of life as he -- a good New England boy who strayed -- has come to know it.

He offers verbal snapshots of the seductive Cambodian people and the lush landscape. He tells anecdotes about the insanity (and the insane profligacy) of on-location movie making. He weaves in a quick personal primer on the political chaos of the region and America's less-than-shining role in helping to foster it. In graphic detail, he profiles the inhumanity of the Khmer Rouge. No less explicit is his account of the fleshpots in Bangkok or his description of the hallucinations he experienced after smoking pot one night at a beach party on the Gulf of Siam.

If that were it, I suppose "Swimming to Cambodia" would be nothing more than an oral travelogue, albeit a defiantly idiosyncratic one. (Gray sits behind a table the whole evening, although he does have at his disposal two maps, a pointer and a microphone, which he relies upon for his more conspiratorial confessions.) But for every step forward he takes in his Cambodian adventure, he takes two backward in time or three sideways in geography.

With merely a pause -- to catch his breath or wet his whistle with a sip of water -- he is suddenly on a train to Chicago with a particularly flaky naval officer, who claims he works in a waterproof chamber in a nuclear battleship and is handcuffed five hours a day next to the green button that sends rockets whizzing toward Russia. Or he's recalling his childhood in Barrington, R.I., and the bullies who first convinced him that he might have a yellow streak up his back, although he's since come to see no shame in that. Or else he's in Hollywood, auditioning for a TV sitcom with a mindless speech about mixed nuts and tradition . . . and not getting the part.

Hither and yon, Gray roams, plucking his cockeyed truths and quirky reminiscences from the air, delivering them in a headlong rush that implies he's got even more on his mind, more stories and thoughts and impressions than he can ever squeeze into an evening. Underneath the apparent disorder, however, is an original and disciplined artistic temperament at work. It is not too much to say that Gray fishes up much of the glory and chaos of our times in the crazy autobiographical net he casts. Talking about himself -- with candor, humor, imagination and the unfailingly bizarre image -- he ends up talking about all of us.

You have to hear him to believe it.