On the deck of a yacht off the coast of Marina Del Ray, Calif.,  Emily Wilson stood out among the 150 guests at the lavish party.  A 40-year-old birthday boy raised his glass of champagne, pointed to her, and said, “I’d especially like to thank my friend Lindsay Lohan for coming out to celebrate with us.” With long red hair and light freckles, Wilson earns more than $600 an hour simply to smile and nod like Lohan.  

Wilson is a celebrity impersonator.

“I think the birthday boy just wanted the crowd to think that he had friends in Hollywood,” Wilson told ABC News, “We were on the water at night, and people had been drinking, so they really thought I was her.”

Emily Wilson, an actress hired as Lindsay Lohan's body double

It was one of  Wilson’s more unusual gigs in the sometimes glamorous and often lucrative industry of celebrity impersonation.

The media recently pounced on Jennifer Lopez for reputedly using a  body double  to film a Fiat car commercial set in the Bronx, and earlier this year, ABC News’ “ 20/20? interviewed ballerina Sarah Lane about her work as Natalie Portman’s double in “Black Swan.”  Behind many of today’s biggest names, there are legions of lookalikes and impersonators making big bucks, often without the stars’ blessings.

Hollywood manager Dan Gore has spent the past 15 years coordinating the careers of professional impersonators.  He discovers celebrity lookalikes in the most ordinary places, including Starbucks and shopping centers, and has gone on to orchestrate world tours for the popular impersonators of Madonna and Michael Jackson who attract crowds of more than 30,000 people in Asia’s stadium venues, where ticket  prices are too low to attract the real McCoys.

“We travel to these countries with a full entourage of body guards, SUVs and publicists. We stay at the nicest hotels, and eat at the nicest restaurants.”  And yes, they even have local groupies.

“The impersonators themselves will sometimes come to expect the rock star lifestyle,” said Gore.

Although posters and marketing material are required by law to note that the impersonators are not authentic, these boundaries are often blurred in third world countries.

Gore admitted it can sometimes be hard for the impersonators to return to their normal lives.  “I tell most of my clients not to quit their day jobs. It’s hard to just be yourself after you experience the power of celebrity.”

Yet Gore acknowledges that impersonation can be a great way to demonstrate acting skills, land a role on “SNL” (Chris Parnell), or even become the frontman of the band Journey (Arnel Pineda).  He helped Wilson transform her gigs as “Lindsay Lohan” into a sustainable acting career.

Wilson moved to L.A. to work as an entertainment reporter after getting a journalism degree from Chapman University in 2007.  But because of her likeness to Lohan, Wilson now walks the red carpet instead of standing behind the rope.

Wilson made her big screen debut in the final scene of spoof movie “Meet the Spartans,” playing Lindsay Lohan as she emerges from rehab.  In 2007, Wilson was hired not to make fun of Lohan but instead served as her  body double  in the film “Poor Things” with Shirley MacLaine .  Directors of busy A-list stars often rely on body doubles  to film noncrucial scenes such as those shot from a distance or from behind the actor.  Not only would Wilson be expected to film some of Lohan’s scenes, Wilson said, “They also had me walk out of the main studio door so paparazzi would take photos of me instead of annoying the real Lohan.”

But after Lohan herself was arrested for a DUI and forced to enter rehab, both Lohan and Wilson lost their roles in “Poor Things,” which was eventually canceled.  In off-screen gigs, Wilson would continue to impersonate Lohan at various events, but found it increasingly hard to imitate the volatile star. “She keeps changing her hair from blonde  to brunette to orange. It gets tiresome.”

So Wilson branched out and recently landed roles in “CSI: NY,” “ How I Met Your Mother,” Entourage and the upcoming film “The Secret Lives of Dorks.”

Jeff Barnett is a Charlie Sheen impersonator

Jeff Burnett, 38, is also building his career based on his resemblance to an existing celebrity. After Charlie Sheen lost control earlier this year, Burnett turned the media spectacle into his own opportunity and now makes $1,000 each time he impersonates Sheen at corporate events. “My nickname in high school was “Buddy Fox” from Sheen’s character in Wall Street,” said Burnett.

After years of working on the Philadelphia Stock Exchange and for Vangaurd as a market analyst, Burnett gave up his career in finance to start a new business and persona in California. He recently hobnobbed with other celebrity look-alikes at the West Hollywood premiere of “The Devil’s Double,” a film about the body double that Saddam Hussein’s son used to avoid assassination attempts.

Single and eight years younger than the real Charlie Sheen, Jeff Barnett says that his role as a Charlie Sheen has improved his love life.  “Women sometimes ask if I need extra goddesses.”  Whenever he signs autographs, he scribbles “The Machine,” one of Charlie’s many nicknames.

But Barnett admits that there are limits to how closely he is able to follow the life of Charlie.  “I can’t handle the kinds of drugs and partying that the man does.”

Barnett hoped that the producers of “Two and a Half Men” would consider him to fill the void left by Sheen, but has resigned himself for now to showing up at corporate events.  His goal is to someday meet Charlie, “I’ve always been compared to him, and I’d just like him to know that I exist.”