"Try to make me interesting," Martin says, when I finish peppering him with questions, demanding names, places, details. He provides a pretty good description of what he calls "Beverly Hills and its environs," which might do for a normal city. But this is Beverly Hills. That requires something more, something extra. So I do the only sensible thing: escape my desk in the flatlands of Texas, slip on my best strategically torn jeans, white shirt, and blue blazer, and fly off to the West Coast. There, I rent a vintage convertible, slide on a pair of sunglasses, and insert Steve Martin's Guide to Beverly Hills into the cassette player.

"It was a place I would pass through," Martin is saying above the roar of the 405 Freeway. "There were a lot of shops that I couldn't afford to go into. I left when I was about 25 and moved to Santa Fe, New Mexico; and then I lived in Aspen, Colorado; and then I came back home, came back to L.A. But you have to understand that L.A. was very smoggy then, and so it was a place to leave. They cleaned it up! So when I came back, I was very surprised. They actually did something about it, and now it seems like it is very sunny and has bright, breathable days. It made it more like home."

From the 405, I take the Santa Monica Boulevard exit and drive east. Turning right on Rodeo Drive - always pronounced Ro-day-o - I enter a different world. The Los Angeles of strip centers, billboards, and disarray becomes orderly, clean, civilized. The sky is as blue as the topaz in the endless jewelry-shop windows, and the sun turns the white concrete brilliant, as if the whole scene were lit like a movie set, making the world's most famous street come alive. There are flowers and sculptures, and the median is festooned with Herb Ritts's and Mario Testino's "Rodeo Drive Walk of Style" photographs. The three-block-long string of shops that Martin once couldn't afford to shop at are lined up like starlets: Gucci, YSL, Ralph Lauren, and the new Rem Koolhaas-designed Prada store, an indescribably futuristic structure in which mannequins are submerged in see-through, Plexiglas-covered manholes in the floor. Everything seems familiar, because it is - from movies and television. It's practically a costar in Pretty Woman.