Some blame the beginning of this trend with 'Tonight Show' host Johnny Carson.

He has also appeared as himself doing 'Tonight Show' monologues or interviews in a large number of movies.

"But I did see the 'Tonight Show' where they said it could hit the Earth."

*There was never a 'Tonight Show' Stone Poneys appearance aired.

"To most people, contemporary art is what Jay Leno makes fun of on the 'Tonight Show,"' said Taylor McKimens, 29, one of the artists.

They want me to be a guest on the 'Tonight Show.'

He was on the 'Tonight Show.'

I did it two weeks after [Conan's 'Tonight Show'] went off the air.

Tearful and angry, he looked straight into the camera and said: "I am leaving the 'Tonight Show.'

"I should never have given the 'Tonight Show' to him," Mr. Paar once cracked.