Lindsey Lohan's Hard-Partying Gal Pal

Their names are synonymous with wild parties and Hollywood night life: Britney, Lindsay, Paris. And, until Britney went into rehab, they were often photographed as a threesome.

But when Lindsay Lohan, 20, had a wild Memorial Day weekend crashing her Mercedes and getting arrested on suspicion of DUI, photos splashed across tabloids from coast to coast of the unravelling actress didn't feature Hilton or Spears. Instead, some showed her passed out in the front seat of a car belonging to a new gal pal: Samantha Ronson.

Now, inquiring minds want to know, just where does Ronson fit in the Lohan loop?

Who Is Samantha Ronson?

Ronson, 29, is a DJ who recently broke out onto the VIP club scene. She's already spun the decks at some of the hippest clubs across America and performed at parties for Maxim and PlayStation, at the Super Bowl, with Lohan on the American Music Awards, at Sundance and the VMAs in Miami.

So why don't most Americans recognize Ronson's name?

Jonathan Jaxson, a former Hollywood publicist and celebrity blogger (, says Ronson's been around for awhile, but has flown under the national radar until recently.

"She's been an indie-house DJ girl forever. She comes really from the woodwork and has risen in fame overnight," said Jaxson.

But what Jaxson calls "forever" really wasn't such a long road for Ronson -- there's already a famous DJ in the industry named Ronson, her older brother Mark. Maya Henderson, a freelance music and club critic in Chicago, says following in her brother's footsteps helped put Ronson on the map.

"Mark Ronson is a very well-known and respected hip-hop producer, which is probably how she got into the scene," Henderson said.

Despite Ronson's efforts to make a name for herself as a DJ, her association with Lohan and company has really put her on the map. So how did a relatively unknown DJ meet up with Hollywood's latest "it" crowd?

It's simple: Like Hilton, Ronson's an heiress.

Confessions of an Heiress

Ronson, hardly a struggling artist with a rags-to-riches story, is the daughter of Anne Dexter-Jones, a renowned New York socialite. Until recently Dexter-Jones was married to Ronson's stepfather, Mick Jones of the '80s rock band Foreigner. The couple divorced in early 2007.

David Patrick Columbia, of the New York Social Diary (, describes Ronson's family background as a little bit social, a little bit rock 'n' roll.

"They really crossed into two different areas, the rock music and the social area," Columbia told ABC News. "That whole world now is so homogenized that it's all kind of one Celebrityville."

Like Hilton, Ronson grew up on the New York social scene, but unlike Hilton, she didn't break into Hollywood or the gossip magazines until recently. She's been a familiar face on the New York Post's Page Six for years.

"She's a big party girl and she's been a big party girl and a big part of that party scene for a long time," said Columbia.

Livin' La Vida Lohan

While Ronson's East Coast socialite status outfitted her with the necessary pedigree for fame and fortune, it's her recently publicized relationship with Lohan that's spreading her name past New York's South Hampton society.

"It's Hollywood. If you want to be famous, get Lindsay in the picture with you and you're going to be famous," said Jaxson. "People are going to wonder who the hell is this Samantha Ronson?"

Jaxson says it doesn't take much to get noticed.

"Any association with Lindsay Lohan, regardless if you even have lunch with her, brings you out into the spotlight," Jaxson said.

But Ronson's done more than just lunch. One of the DJ's earliest known associations with Lohan may be their work on the same film in 2004. Ronson's single "Built This Way" appeared in Lohan's breakout hit movie "Mean Girls."

But Jaxson says the two go even further back than that. "Sam's a good friend of Lindsay's. They've been friends for a long time," he said.

Jaxson says the two are actually romantically involved. "I hung out with them in March in New York and revealed on my blog that Sam and Lindsay were dating," said Jaxson.

Lohan and Ronson have yet to address that rumor publicly. And Lohan was recently photographed cavorting in the Caribbean with model Callum Best.

Lohan Back in Rehab -- Is Ronson Responsible?

Is that close friendship, or even relationship, affecting Lohan negatively?

Ronson was by Lohan's side during most of the wild holiday weekend. It is rumored that it was Ronson leaving Lohan's apartment that prompted the star to get in her car and chase after the DJ, only to crash on the way back to the apartment. Lohan was arrested after the incident early Saturday morning.

Two days later, photos of Lohan passed out in the front seat of Ronson's car are making national and international news. Lohan has returned to rehab at Promises in Los Angeles.

"Now you have these very young actresses like Lindsay Lohan who are spending themselves on their night life and they always attract a group of people who are a part of that world and Samantha Ronson is a major part of that world. She's a downtown DJ," said Columbia.

But Jaxson says Ronson isn't acting like a real friend.

"All these people say they want to help Lindsay, but nobody's telling her to stop doing the drugs. … Everybody encourages her," said Jaxson.

DJ Sam -- Can Her Career Stand Alone?

With Lohan back in rehab, will Ronson's budding DJ career be able to survive without her famous promoter?

Henderson has her doubts. She says it's Ronson's celebrity associations that bring the crowds, not her musical talents. After a recent performance in Chicago, Henderson said that Ronson was unimpressive and that she had the right tools to be a successful DJ but lacked talent.

"It's easier to be a DJ now because of MP3 files. It looks like you're spinning, but you're really just playing music off the computer," said Henderson. "As far as turntable skills, I didn't see any of that from her."

Without a successful career to carry her name, will Ronson continue to be a name by association at least?

Jaxson says no. He thinks Ronson's celebrity will fade just as quickly as her music career. "She's only been really out there a couple of months. She'll die out like all the others," said Jaxson.

Only time and the tabloids can tell.