Kevin Federline parodied his public persona with a much-talked-about appearance in a Nationwide Insurance commercial during Sunday’s Super Bowl. The former Mr. Britney Spears showed himself enjoying the perks of rap stardom before waking up to reality: Clad in a red uniform, he operated a deep fryer at a fast-food joint.

For once, Federline had done something hip. Self-skewering has come into vogue. Self-parodies allow celebrities to show themselves in a light more flattering than the one they’re usually seen in. I’m not really as bad as you think I am, they seem to say. It’s just a persona. I’m in on the joke.

HBO’s new comedy Extras unleashes new examples week after week. In a recent episode 17-year-old Daniel Radcliffe, of Harry Potter fame, played on the idea that he’s trying way too hard to escape his boy-wizard image.

Dressed in his wizard costume, he tried to seduce an older woman. "I’ve done it with a girl," he said.

Also on the show this season, Orlando Bloom played a version of Orlando Bloom so enamored of himself that he couldn’t believe any woman could find him unattractive. Last season Ben Stiller portrayed himself as a nasty, hateful director.

Coldplay’s Chris Martin is known for shamelessly promoting his pet cause. During most performances, "MTF" (for "make trade fair") is written on his hands. In a cameo appearance, Martin played an opportunistic version of himself, using his cause to sell his music. When he showed up to record a public-service announcement, he unbuttoned an outer shirt to reveal another promoting a new Coldplay greatest-hits album. (It doesn’t really exist.)

Ron Simon, a curator of the Museum of Television and Radio, says that since the variety shows of the 1950s, TV shows have allowed celebrities to mock themselves.

Peter Lorre, a film actor known for his dark roles, went on Milton Berle’s Texaco Star Theater in the 1950s, said Simon, because he wanted to be seen in a softer light.

Richard Nixon, during the 1968 presidential campaign, went on Rowan & Martin’s Laugh-In to say, "Sock it to me." It was a sly reference to his famous "you won’t have Nixon to kick around" rant, which dogged him after a failed gubernatorial campaign in California.

Recently, the pace of self-parody on TV has quickened. On Entourage, guest stars ranging from Bob Saget to Seth Green have taken digs at themselves.

Animated shows often promote the idea that a public persona is a cartoon. Family Guy has long included a self-parody of Batman TV actor Adam West, who also mocked himself on The Simpsons. South Park self-parodies itself with a show-within-a-show. As a response to critics’ accusations that the show was crude, sloppily animated characters Terrence and Phillip pass gas even more than the show’s regular characters.

K-Fed’s Super Bowl ad marked Nationwide’s third self-parody spot in as many years. MC Hammer made fun of his status as one-hit wonder in the first. The second found Fabio flashing forward to his future as a flabby, gray-haired model.

Becca Cragin, professor of pop culture at Bowling Green State University in Ohio, said the trend reflects changing tastes.

"Audiences are becoming a lot more sophisticated," she said, "so they appreciate irony and more complex humor strategies."

But self-parody, she said, requires a delicate balancing act. You can come off egotistical or clunky by trying too hard.

Or you can dig out of an embarrassing situation. The Museum of Television and Radio’s Simon said that when a celebrity puts himself in an uncomfortable spot, it "humanizes" him. After Hugh Grant’s encounter with a prostitute became public, he made talk-show appearances poking fun at himself and was quickly forgiven.

"I think self-parody is a policy of desperation," said Simon Dentith, a British author who wrote a book about parody. But he also said the actors who do it right come "from a position of cultural confidence."

Meaning Stiller and Radcliffe have nothing to lose from a self-deprecating turn on Extras.

Federline, on the other hand, is in a desperate situation. His rap album, released last year, was a flop. His marriage to Britney Spears, the thing that made him famous, has dissolved. And his public persona is that of a lazy, gold-digging partyer.

Steven Schreibman, president of advertising and brand management for Nationwide, said these ads show the celebs "are smart enough to make fun of themselves."

Federline’s hope, one can assume, is that the American public comes to love him.

But Cragin’s not convinced it’ll work. Federline, she says, "really seems to have a profound lack of talent."

In that case, his parody wouldn’t be parody at all. It would be his sad reality.