Evan Richards lays down the ground rules. “If we happen to spot a celebrity on the tour,” says the amiable, 20-something tour guide for Warner Brothers Studios, “please remain calm.” No sooner has the word “celeb” rolled off his tongue than riders in the back of the 12-seater golf cart are giggling and removing their camera lens caps, scanning the horizon like cheetahs. “This isn’t a celebrity safari, guys,” Richards jokes as we mount the final speedbump before entering the famous Warner Brothers lot. “You can’t be like, ‘There’s George Clooney, go get him!’”

Wanna bet?

Nothing complements a visit to Los Angeles like a genuine celebrity sighting, better still if you have the pictures to prove it. No one question is asked more often to those returning home from a trip to Los Angeles than “Did you see any movie stars?” A visitor to L.A. is somehow expected to dine alongside Tom Hanks or rollerblade behind Jennifer Aniston. The folks back home demand it.

There are two seasons in Hollywood, summer and Oscar. Summer in Los Angeles is characterized by warm, sunny days and comfortable, dry nights. During Oscar season, which runs roughly from late November through March, the town goes giddy. Celebrities are out in full force, touting films. Ads promoting movies run in papers, on the sides of buildings, on billboards, on bus stops, on buses. “Film of the Year” becomes a mantra. What better time to visit Los Angeles for some serious starspotting?
Evan, the hunt is on.

We don’t see George Clooney on the Warner Brothers lot, but we do see the fiberglass-brick brownstone that was his apartment on “ER.” Evan points out nearly a hundred famous façades. Within three blocks we travel from New York to Chicago to Montreal. We see street sets used in films such as Spiderman, Minority Report, and Casablanca. But no movie stars. Instead, we learn that movie snow is sometimes flakes of instant mashed potatoes and that Lauren Graham from “Gilmore Girls” once almost crashed her bike into Evan’s golf cart. We see “ER”’s County General Hospital and the White House portico entrance from “The West Wing.” We visit the set of “Two and a Half Men.”

“These shows cannot be done without an audience,” Evan tells us. “They need 250 people to sit here and let them know what’s funny.” Still, no movie stars. The closest thing we see to a celebrity is an empty parking space with the name M. LeBlanc stenciled on the curb.

One of the final stops on the Warner Brothers tour is Central Perk. Yes, that’s the Central Perk set from “Friends” fame. Seated on the couch where the Friends spent so many seasons sipping lattes and bemoaning love, less than 15 feet from where Phoebe sang “Smelly Cat,” I meet Devra and Adam Glick from New York City. I ask Devra what they plan to do while visiting L.A., and she rattles off an itinerary straight out of People magazine or Us Weekly. Devra has done her homework: Toast for breakfast, Warner Brothers Studios, The Ivy for lunch, Koi for dinner, and, oh, can’t forget shopping at Kitson on Robertson Blvd. “Sounds like you planned this trip just to see celebrities,” I say. “Are you kidding me?” Devra squeals. “Absolutely.” Adam casts a glance my way that says, “Man, you don’t even know.” Last night, Devra says, they saw the dad from “One Tree Hill” at the fashionable restaurant Asia de Cuba, but Devra has her sights on bigger game. “I’m afraid to say who I want to see because then I might jinx it,” she says. Devra and I compare notes and she agrees to report back later on her progress.

My next stop is the obligatory tour of the stars homes. Tour guide David Kettlewell, of LACityTours.com, has been leading tours past the homes of the rich and famous for 14 years. He counts Rod Stewart, Cindy Crawford, Nicolas Cage, Richard Gere, and Jack Nicholson as some of his biggest sightings. Kettlewell offers a primer on starspotting. “Ultimately, it’s all about timing,” he says, but it’s also important not to anticipate the obvious. He explains that many celebrities pass unnoticed because visitors to Los Angeles expect limousines and flashbulbs to announce a stars' arrival. Remember that stars are people, too, Kettlewell says, and their lives are filled with mundane tasks like shuttling children to piano lessons, choosing sink fixtures, and buying pet food. More often than not, a star sighting consists of Bruce Willis getting his car washed or Jessica Simpson thumbing through a magazine in Walgreen’s. They don’t go out of their way to get your attention. “A lot of them don’t dress up. They go unshaven, wear sweatpants, and lay low so they don’t get recognized.”

I spend the next three hours on the tour weaving through some of the most exclusive neighborhoods in Los Angeles. The tour is a gas, but there are a lot of should-have-been-here-yesterday-type moments. On Mulholland Drive, we pass the home of Cuba Gooding Jr., and Kettlewell says, “We saw him gardening in the yard last Saturday.” We see the former home of Britney Spears and a formidable black metal gate fronting the path to a home where Kettlewell says Marlon Brando lived until his death. Jim Carrey’s home apparently includes an Olympic-sized swimming pool and a 9-hole golf course. We pass Julia Roberts' driveway and John Travolta’s front door. A group of tourists are gawking at Leonardo DiCaprio’s home. David points out the houses from “The Beverly Hillbillies” and “The Fresh Prince of Bel Air.” We stop on Beverly Hills’ swanky Rodeo Drive and Kettlewell lets us off the bus for 20 minutes. “Keep your eyes open,” he says, “this is one of the best places in L.A. to see movie stars. Eight days ago we saw Brad Pitt here.” In front of the Regent Beverly Wilshire Hotel, recognizable as the hotel from Pretty Woman, a young woman on our tour screams “Limo, limo, limo,” and points to a stretch black limo approaching the curb. “Oh, he’s got the window down,” she shouts, jumping up and down. Alas, the door opens and it’s nobody famous. We should have been here yesterday.

Later that evening, I retrieve an excited message on my cellphone, “Hi. This is Devra Glick. Just wanted to give you the full report on our celebrity sightings at Koi tonight. We saw Ryan Seacrest. We also saw Fred Durst from Limp Bizkit and Mario Lopez, aka A.C. Slater, and, um…I did take a picture with, um…Ryan Seacrest.” Okay, apparently I’ve been going about this all wrong. Time to hit the restaurants.

The next few days are a hazy collage of sushi, steak, wine, valet parking, and martinis. Breakfast is quesadillas and wheatgrass martinis at Oliver in Sports Club LA in Beverly Hills. David Spade is a regular. Didn’t see him. Lunch is The Ivy (a longtime haven for Hollywood movers and shakers). Make reservations, sit on the patio, bring money, feel like a movie star, but don’t see any. Another lunch is at Global Cuisine at The Lot. Celebrity sightings depend on what’s being filmed nearby. Jodie Foster was in recently, so was Drew Barrymore, Jennifer Love Hewitt, and Lindsay Lohan. Try the Vietnamese Steak Wraps. Celebrities? Nada. Dinner is at the Sterling Steakhouse. I recommend the Lamb Chops and the Truffle Scented Macaroni and Cheese. Bruce Willis recently jammed with the band, Ben Stiller celebrated a star-studded birthday here. I grow fatter — but no celebs. The next dinner is at Katana. Fabulous sushi. Paris Hilton is a regular. I see Kato Kaelin. (Does that count?) The next meal is at the ultra-trendy Koi. More sushi, paparazzi camped outside. I eat, I wait. Finally, I see Rumer Willis (offspring of Demi and Bruce). Does that count? I then choose the Geisha House, of which Ashton Kutcher is an investor. More sushi, no Kutcher. OK, I reason, I’m sure I’ll have luck at Dominick’s. Opened in 1948, it was a Rat Pack hangout. Its new investors are Ben Harper and Laura Dern. I eat homestyle Italian, enjoy great cocktails, and — boom! — 20 feet away sits Kiefer Sutherland. Score. For a nightclub, I choose the Cabana Club. Best on Thursday nights, I hear. I see its great pool and waterfalls. But no celebrities. Next stop is the Tropicana Bar in the historic Hollywood Roosevelt Hotel. Here, you dress nice, bring money, and hopefully know someone. Score again: I spot Leelee Sobieski, Mark McGrath, and Adrian Grenier of HBO’s “Entourage.” I try not to fall into swimming pool as I crane my neck.

But this is Oscar season. Where are all the heavies? Where are the A-listers? I’m not leaving this town without a trophy.

When all else fails, go for the safety net. My savior is a comprehensive Web site: seeing-stars.com. The site posts a running list of all movie premieres and star cere-monies (where celebs receive a star on Hollywood Boulevard’s Walk of Fame) taking place in Los Angeles, complete with time, location, and a list of stars expected to attend. I pick Woody Allen’s Match Point, at the Los Angeles County Museum of Art.

I show up an hour early and find a roped-off section specifically for lookie-loos next to the fabled red carpet. I meet a seasoned starspotter named Kelly Buchwald, from nearby Monrovia, California. She’s been to at least 25 of these events, she says. “What’s the protocol?” I ask. “Basically we scream and they come over and sign autographs,” Kelly says. Sounds fairly straightforward. When the appointed time comes and goes, Kelly explains that the stars like to be fashionably late. “But once you see somebody that you know,” she says, “you’re going to be so excited, you’re going to forget all about the time.” Just then the limos arrive and the scene explodes. Kelly is yelling, and the press photographers are shouting and jockeying for position. The camera flashes create a strobe effect. Time stands still as Scarlett Johansson saunters by, followed by Woody Allen, Chris Rock, and a host of others. As quickly as it started, it’s over, and the lights dim. “I’ve seen Chris Rock two times before,” Kelly says, “but I’ve never been able to get an autograph.” “Third time’s a charm,” she says, holding up a signature. I’ve bagged my quarry, too. The safari is nearly complete.

Before leaving town, I decide to catch a taping of “The Tonight Show,” shot live on the NBC lot in Burbank. I get free tickets from tvtix.com and show up at the studio an hour in advance. The Web site can’t tell you the guest lineup when you receive your tickets, because the studio doesn’t always release that information. But I’m not surprised to learn that George Clooney is the featured guest. It is Oscar season after all. He touts his movie Syriana and jokes with Leno about gaining 30 pounds for the film, a new look for Clooney, and one that might show up on a tourist’s developed film roll any day now.