LOS ANGELES - The first strike by Hollywood writers in nearly 20 years got under way Monday with noisy pickets on both coasts — a walkout that threatens to disrupt everything from late-night talk shows to soap operas.

The strike began after daylong talks Sunday failed to produce an agreement on payment to writers from shows offered on he Internet.

"The Tonight Show" on NBC will immediately go into reruns, according to a network official who spoke on condition of anonymity because the person lacked authorization to comment publicly.

KTLA-TV reported that fans of the "Ellen" talk show were told at the NBC lot in Burbank that there would be no taping on Monday.

Comedy Central previously said "The Daily Show with Jon Stewart" and "The Colbert Report" would likely go into repeats as well.

The strike will not immediately impact production of movies or prime-time TV programs. Most studios have stockpiled dozens of movie scripts, and TV shows have enough scripts or completed shows in hand to last until early next year.

At the CBS lot in Studio City, about 40 people hoisted signs and applauded when midmorning picketing began.

Robert Port, a writer for the TV show "Numb3rs," said he was as ready as possible for what could be a long walkout.

"We live in Los Angeles, your bank account can never really for ready for this," he said.

Across town at the Paramount Pictures lot on Melrose Avenue, about 50 strikers dressed in jeans, athletic shoes and red strike T-shirts carried signs reading, "Writers Guild of America on Strike."

Drivers honked their horns as they passed the studio's landmark gate.

The first noisy strikers appeared outside the "Today" show set at Rockefeller Center in New York, where NBC is headquartered. The "Today" show is not directly affected by the strike because news writers are part of a different union.

A giant, inflated rat was displayed, as about 40 people shouted, "No contract, no shows!"

"They claim that the new media is still too new to structure a model for compensation," said Jose Arroyo, a writer for "Late Night with Conan O'Brien."

"We say give us a percentage so if they make money, we make money," Arroyo said.

Diana Son, a writer for "Law & Order: Criminal Intent," said she has three children and getting residuals was the only way she could take time off after giving birth.

"It's an extremely volatile industry," said Son. "There's no job security. Residuals are an important part of our income. There's no cushion."

Millie Kapzen of Memphis, Tenn., who watched the New York pickets from across the street, said she was "disgusted. ... I really think they should try harder to negotiate."

Kapzen said she sells advertising for radio stations. "We've already had cancellations of sweeps weeks ads" by the networks.

The strike is the first walkout by writers since 1988. That work stoppage lasted 22 weeks and cost the industry more than $500 million.

Talks began in July and continued after the contract expired Wednesday. Writers and producers gathered for last-minute negotiations Sunday at the request of a federal mediator.

They met for nearly 11 hours before East Coast members of the writers union announced on their Web site that the strike had begun for their 4,000 members.

The Alliance of Motion Picture and Television Producers said writers refused a request to "stop the clock" on the planned strike while talks continued.

"It is unfortunate that they choose to take this irresponsible action," the alliance said in a statement.

Producers said writers were not willing to compromise on major issues.

Writers said they withdrew a proposal to increase their share of revenue from the sale of DVDs that had been a stumbling block for producers.

They also said proposals by producers in the area of Internet reuse of TV episodes and films were unacceptable.

"The AMPTP made no response to any of the other proposals that the WGA has made since July," writers said in a statement.

In Los Angeles, writers planned to picket 14 studio locations in four-hour shifts from 9 a.m. to 5 p.m. each day until a new deal is reached.

Security was stepped up at the Bob Hope Drive gate, across from Johnny Carson Park, in Burbank. Guards were on duty and Burbank police squad cars cruised past the site.

One key factor that could determine the damage caused by the strike is whether members of a powerful Hollywood Teamsters local honor the picket lines.

Local 399, which represents truck drivers, casting directors and location managers, had told its members that as a union, it has a legal obligation to honor its contracts with producers.

But the clause does not apply to individuals, who are protected by federal law from employer retribution if they decide to honor picket lines, the local said.

The battle has broad implications for the way Hollywood does business, since whatever deal is struck by writers will likely be used as a template for talks with actors and directors, whose contracts expire next June.

"We'll get what they get," Screen Actors Guild president Alan Rosenberg told The Associated Press.