For a guy who on Friday said he thought all the media attention he was getting was "kind of silly," American TV's first game-show millionaire sure was into it by yesterday, appearing on ABC's "Good Morning America," syndicated "Live With Regis and Kathie Lee" and CBS's "Late Show With David Letterman."

"I'm thinking gambling," John Carpenter joked when Letterman asked him what he was going to do with his winnings.

Can this be the same drab guy who was seen by about 22 million Americans bagging a million bucks last week on ABC's hit quiz show "Who Wants to Be a Millionaire"? Carpenter, who lives in Hamden, Conn., was the first "Millionaire" contestant to win the top prize.

The 31-year-old Carpenter's TV transformation actually started Saturday night, when he made a "surprise" appearance on NBC's "Saturday Night Live."

Appearing in the opening sketch, cast member Darrell Hammond--playing potential Reform Party candidate Donald Trump--announced that Carpenter had been picked to be his running mate. Carpenter then pretended to call his dad--kinda like he pretended to do on the quiz show last week--then opened the show by shouting "Live from New York, it's 'Saturday Night!' "

Yesterday morning, on "GMA," Carpenter called the "SNL" experience "incredible."

After "GMA," Carpenter turned up on "Live With Regis and Kathie Lee" to collect his check.

"Don't cheat on your income tax," co-host Kathie Lee Gifford told him, "because the whole world knows what you've won."

"I wouldn't dream of it," said Carpenter, who works for the IRS. Get it? Good one, Kathie Lee!

Carpenter's appearance on the syndicated show was no coincidence. Gifford's on-air partner, Regis Philbin, moonlights as host of ABC's game show hit. During Friday's game-cast (it actually was taped Thursday), Carpenter had several times prevented Rege from uttering his now trademark "Is that your final answer?" line by saying that his choice was his final answer.

Yesterday, Philbin apparently still hadn't forgiven Carpenter, whom he described as having ice water in his veins. "On a couple of those questions he looked across the table and sneered at me," Philbin said.

"When I looked at the tape, I looked a little more cocky and self-assured than I really wanted," Carpenter acknowledged. But, he explained, "I knew the answers as soon as I saw the questions."

Yeah, well half of America knew the answers to those questions.

Earlier yesterday morning "Good Morning America" struggled to squeeze stuff out of Carpenter.

Charlie Gibson took the first whack at it, breaking the ice by complimenting Carpenter on cutting Philbin cold.

"You didn't even let him ask, 'John, is that your final answer?' That's terrific, that's terrific," Gibson said.

He then asked Carpenter if he had been surprised that the million-dollar question was so easy.

"Well, the only other million-dollar question I saw I thought was really easy, too," Carpenter replied.

(That was the one about Jethro Tull winning the first Grammy for best hard rock/metal performance.)

Later in the show, Elizabeth Vargas took her turn trying to get at what makes John Carpenter tick.

Debbie Carpenter, John's wife, told Vargas she had encouraged her husband to go on "Millionaire" because she knew he'd be good at it.

"We always saw 'Jeopardy!' . . . He knows every answer, he shouts them out," she confided.

Wait a minute. Last Friday, during a group hug on the phone with The Reporters Who Cover Television, Carpenter said he doesn't watch TV except for sports and "The Simpsons" and that before "Millionaire" he was "against" game shows.

I am shocked.

By last night, when Carpenter was cooking on CBS, he told Letterman he wouldn't consider going on "Jeopardy!"

"Not enough money," he cracked.

Looks like another "Seinfeld" cast member will be returning soon to series TV. Jason Alexander, a k a George Costanza, has made an exclusive two-year deal with 20th Century Fox TV that includes putting him back into a prime-time show by early 2001.

The trade paper Variety reports that once the series is set with a network, Alexander is expected to make about $200,000 per episode and the network getting the show will pay most of that tab. And that a 22-episode commitment is "considered all but a given," according to industry insiders.

That's Hollywood talk for: Alexander wants to be paid $200,000 per episode and the studio is going to try to stick the network that buys the project with the bill.

Alexander's a few months behind "Seinfeld" alum Michael Richards, a k a Cosmo Kramer, who already has a network lined up. NBC has guaranteed it'll pick up at least six episodes of a new detective sitcom starring Richards, written by some "Seinfeld" writers. That project will debut in the spring--or next fall.

Jessalyn Gilsig ("The Horse Whisperer") is close to signing on as a regular on David E. Kelley's new ABC drama series "Snoops." Gilsig will join the cast in mid-January; series co-star Paula Marshall's character is going to be killed off.