Seth Rogen has fulfilled a dream, and he's not talking about his hit movie "Knocked Up" or playing a superhero in the upcoming "The Green Hornet."

Rogen co-wrote an episode of "The Simpsons" and lends his voice to a character in tomorrow's episode.

"As a writer, it always just seemed like the Holy Grail," Rogen said of the animated series. "I can die a happy man now."

In "Homer the Whopper," Rogen plays a trainer assigned to get Homer in shape to play Everyman, a comic book hero created by the rotund couch potato.

SHAKUR'S LYRICS IN LITERARY ARCHIVES

Tupac Shakur's mother has donated a collection of the late rapper's writing to the Robert W. Woodruff Library's archives at Atlanta University Center.

Afeni Shakur gave more than 150 of her son's items, from rough drafts of lyrics and poems to a photocopy of his contract with Suge Knight and Death Row Records.

Shakur was a top-selling rapper, especially after his 1995 release from prison, He was shot to death while riding in a car with Knight in Las Vegas a year later.

CONAN HEAD INJURY STOPS 'TONIGHT SHOW'

Conan O'Brien hit his head during a stunt for the "Tonight Show" yesterday and the production was halted, NBC said. The network would not reveal his condition or say if he was hospitalized. But a person close to the production, speaking on condition of anonymity, said O'Brien was being checked at a hospital.

O'Brien, 46, issued a statement through NBC that indicated he was treating the incident lightly: "Last thing I remember I was enjoying the play with Mrs. Lincoln, and the next thing I knew I was in bed being served cookies and juice."

ROWLING CHIRPS UP ON TWITTER

The real J.K. Rowling has come to Twitter.

To counter numerous fake Rowlings on Twitter, the Harry Potter author has set up her own account. But she warned that she doesn't plan many tweets.

"I should flag up now that although I could twitter endlessly, I'm afraid you won't be hearing from me very often as pen and paper is my priority at the moment," she wrote in a tweet dated Sept. 17.

The account, www.twitter.com/jk-rowling, was first reported yesterday by the fan site www.the-leaky-cauldron.org, then confirmed by publisher Scholastic Inc.