When Tom Waits shambled into court in the spring of 1990, the jury was clueless. "The first time I saw him, I thought this was a criminal case and he was a criminal," recalled one juror.

But the disheveled-looking witness was actually the plaintiff, and he was in court to protect a multimillion-dollar asset: his own voice.

For years, advertisers had been in the habit of hiring musicians to record jingles that sounded suspiciously like well-known popular singers. When Bruce Springsteen refused offers to license his huge hit 'Born in the USA,' companies from Miller beer to Chrysler developed commercials with "original" songs that blatantly mimicked the Boss's workingman determination. "I work an honest day/I want an honest deal," went the lyrics to one Safeway supermarkets ad.

Advertisers began to shy away from the practice after Bette Midler sued Ford for $10 million in 1988. After she declined an offer to license her version of the Bobby Freeman oldie 'Do You Want to Dance,' Ford's advertising agency hired one of Midler's backup singers to record a soundalike version.

Waits, known for his distinctively raspy singing style and his bohemian art songs, had been outspoken for years about his aversion to advertising. ("If Michael Jackson wants to work for Pepsi, why doesn't he just get himself a suit and an office in their headquarters and be done with it?" he wondered.) When an ad agency requested a Waits performance for a Diet Coke ad, "you never heard anybody say no so fast in your life," a producer said.

Amazingly, the same agency hired a dead ringer for Waits -- a Dallas musician named Stephen Carter, who'd been singing Waits' songs for years -- to record a song for Frito-Lay's new SalsaRio Doritos. The jingle was unmistakably based on Waits' carnival-barker burlesque, 'Step Right Up.'

Carter, a big fan, surely knew that 'Step Right Up' was actually written as "an indictment of advertising," as Waits described it. He also knew that his hero wasn't going to be happy, but the agency went ahead with the ad. Waits was making an appearance on a Los Angeles station when he first heard it. Within a month, his lawyers had filed suit against Frito-Lay.

Waits was ultimately awarded more than $2 million in damages for "voice misappropriation." "Now I have a fence around my larynxization," said the inimitable songwriter upon announcement of the verdict.

More recently, though, a few stubborn advertisers have been caught on the wrong side of that fence. Within the past few years, Waits has been compelled to sue at least two more advertisers for soundalike commercials. After the second suit, against car manufacturer Opel in Germany, Waits released a statement: "I'm glad to be out of the car sales business once and for all." Or at least until Michael Jackson takes that corner office at Pepsi.