And in Hollywood, you're nobody until you've worked with "The Simpsons'" incredible core voice-over talent provided by Dan Castellaneta, Hank Azaria, Nancy Cartwright, Harry Shearer, Julie Kavner and Yeardley Smith.

Many huge stars from all walks of life waiting to record their lines - either as themselves or in character - in a small, windowless recording studio on the 20th Century Fox lot on L.A.'s west side literally shook in terror as they waited to go on with the intrepid "Simpsons" crew. One can only imagine who among the likes of Bono, Paul Newman, Kiefer Sutherland, Ludacris, The White Stripes, Eric Idle, Tom Wolfe, Gore Vidal, Mick Jagger and Ricky Gervais betrayed their cool with slight tremors cropping up from the fingertips to the larynx.

"The one thing that still surprises me is that lots of celebrities who come to work with us on 'The Simpsons' are very nervous about it," said Yeardley Smith, 43, the voice of 8-year-old Lisa Simpson since the show's debut as a 30-second spot on "The Tracey Ullman Show" on April 19, 1987. As a regular 30-minute series created by cartoonist Matt Groening, the show went prime time on Jan. 14, 1990.

"These huge celebrities, and their children, are there because they're genuine fans of the show," Smith continued. "And some of them really are afraid to screw up. It's like, 'Oh, my God, you guys are so incredible and awesome that I'll never measure up!' Then, it becomes our job to put them at ease. Most of us think, 'Are you high? What's the matter with you? You are the huge star, you are the icon, you're the big, big thing.' Still, it tickles me."

For Smith - who has verbally portrayed the smart, saxophone-playing vegetarian for nearly half her life - Lisa Simpson is a dream job, particularly since she is the only performer in the regular cast who only provides one voice for the show; others do a variety of characters, including Castellaneta (Homer, Krusty, Grandpa), Azaria (Moe, Apu, Chief Wiggum), Shearer (Mr. Burns, Ned Flanders, Smithers), Kavner (Marge, Selma, Patty) and Cartwright (Bart, Ralph Wiggum, Nelson).

"A 'Simpsons' casting director happened to see me in a play called 'Livin' on Salvation Street' at a tiny theater shortly after I arrived in Los Angeles," Smith explained. "I played Wilma, a tomboy who sang Elvis Presley songs and wanted to join the Army. Several months later, the casting person remembered my performance and called me in to read, first for Bart, but I sounded too much like a girl, then Lisa."

She was handed a drawing of Lisa for inspiration in order to find the right voice.

"But in the original picture they handed me, the Simpson family wasn't nearly as cute as they are today," said Smith. "In fact, they were really ugly and spiky - much like Matt (Groening's) 'Life in Hell' characters. I only responded to the fact that she was only 8 years old. So I took my voice up a tiny bit when they recorded my lines. ... It was the easiest job I ever got."

Smith was born in Paris while her father - Joseph Yeardley Smith - was a UPI correspondent, but she was raised in Washington, D.C., when he became the obituary editor for the Washington Post. Her mother, Martha Mayor, spent the bulk of her career as a paper conservator for the Smithsonian's Freer Gallery of Art. Thomas, her older brother, now works for the state of Maine supervising the cleanup of oil.

The petite actress always knew she would be part of theaters and sound stages.

"They were places where I could be whomever I wanted and needed to be," Smith recalled. "With lots of support from my mother, I made my professional acting debut at a dinner theater in Washington when I was 14 as Tinkerbell in a plagiarized version of 'Peter Pan.' A year later, I understudied Cynthia Nixon in 'The Real Thing' on Broadway and soon moved to L.A. for TV and film."

Married to writer Daniel Erickson, Smith is also looking for extra income when her first children's novel, "I, Lorelei," is published next winter by HarperCollins. Life is good since conquering bulimia, which nearly destroyed her existence from the age of 14 to 37.

"An eating disorder, bulimia is all about self-esteem and is a coping mechanism that never works out very well. After all the years of binging and purging, I found an outpatient program at UCLA that met twice a week for 13 months. Gradually, the feeling of worthlessness went away."