Jay Leno is an Emmy-winning American comedian who is best known as the current host of NBC television’s long-running variety and talk program ?The Tonight Show?. He also owns Big Dog Productions, a company that co-produces the show.
Since becoming the host of the ?Tonight Show?, Leno has made a number of cameo appearances, usually appearing as a talk show host or making fun of his famous chin. These cameos include the sitcoms ?The Drew Carey Show?, ?Friends?, ?The Nanny?, ?Fresh Prince of Bel-Air?, and ?Titus?, as well as the animated shows ?The Simpsons?, ?South Park?, and ?Family Guy?.
Leno took over ?The Tonight Show? in 1992 when Johnny Carson retired.
Source - http://en.wikipedia.org/wiki/Jay_leno