Dan Castellaneta is little-known actor and voice of Homer Simpson

A thin, balding man sits in the corner of the trendy Villa Sorriso restaurant. He is one of the invited guests at a party being thrown by the Fox Network. Stars from all of the network shows are in attendance.

The man, who almost goes unnoticed, is actually one of the network's biggest stars. Since 1989, Dan Castellaneta has provided the voice for Homer Simpson and a host of other characters on "The Simpsons."

The animated story of the family from a town named Springfield has been a top-rated Fox show for years. And now, the clan has made the leap to the big screen. "The Simpsons Movie" opens in theaters today.

Castellaneta's talent to create voices for animated characters first began to emerge when he was growing up in Chicago in the '60s.

"When I would watch cartoons, I was able to do some of the voices," Castellaneta says. "My father was a bit of an amateur actor and he could do accents. I would watch movies and try to do the accents."

The show has certainly tested his ability to do a variety of voices. Along with his work as Homer, Castellaneta also provides the voices for numerous other "Simpsons" characters: Krusty the Clown, Grampa Simpsons, Santa's Little Helper, Barney Gumble, Groundskeeper Willie, Mayor Quimby, Sideshow Mel and Itchy.

In the early years, the show's cast would be asked to audition to provide any new voices. Now, explains Castellaneta, the producers just know what the cast members can do and assigns them the characters.

"There are times where some voices have been slotted for a guest star and then they couldn't do it. They wind up using our voices," Castellaneta says.

Inspiration for the voices comes from a variety of sources.

For instance, Krusty's raspy voice was inspired by the Bozo the Clown that aired on Chicago television when Castellaneta was young.

Castellaneta may be the actor of 100 voices for "The Simpsons" but he becomes almost mute in regards to the new feature film. He will give up no details of the plot.

The voice actor will say the only real difference for the actors between their regular small-screen duties and work for the movie was that more time was taken to record the vocals.

The fact a movie has actually been made should be reason enough to shout. There has been talk of a big screen version of the TV show for years.

Castellaneta says he paid no attention to the talk. He always knew a movie would be made when the time was right.

"The excitement about doing the movie is the challenge of doing it and raising things up a notch for a film audience in terms of the acting," Castellaneta says.