Not since the Love Boat sailed have C-list celebs enjoyed such a sunny return to the spotlight.

From Fox's Celebrity Boxing to E!'s Anna Nicole Smith Show, celebrity reality TV has created an insatiable demand for once-familiar faces.

Barry "Greg Brady" Williams, for example, has appeared on Celebrity Boxing, Celebrity Boot Camp and Celebrity Fear Factor, proving that being a has-been star can be a career in itself.

"It's because (audiences) are seeing someone they connect with," explained rap star Coolio, who has appeared on Celebrity Boot Camp and Celebrity Fear Factor.

There may be more on the way. CBS is developing star versions of Big Brother and Survivor. And E! is launching a myriad of shows including Star Dates, which sets singles up on blind dates with the likes of Gary Coleman and Butch Patrick (Eddie on The Munsters).

Even if execs could book big Hollywood names, it's the blast-from-the-past people who viewers tune in to see, said Jeff Shore, vice president of development for E! Networks.

"The better ratings are for people who have fallen out of the public eye," said Shore. "People have this fascination for where they are and what's become of them."

Audiences relate to actors and shows the same way they do to music, identifying with their own generation, Shore said.

So it's not surprising the retro craze for the '70s and '80s has coincided with younger baby boomers and older Gen-Xers gaining power in the media world.

"People reach a time in their lives when they start looking back, not forward," Shore said.

But some critics say there's a big difference between the dormant public love that fueled John Travolta's comeback and the circumstances that landed his Welcome Back Kotter castmate Ron "Arnold Horshack" Palillo, in Fox's celebrity boxing ring.

"I don't think these shows show any form of respect or nostalgia. These people have become caricatures and punch lines," said Matthew Felling, director of the Center for Media Study and Public Affairs. "No (celebrity) has ever walked away from these shows with more cache. We don't walk away from these shows thinking better of someone."

Claes Bell, a student at Florida State University who writes the TV and movie reviews for the school paper, said that as a viewer, it depresses him to see his beloved Brady kids showing up on these programs.

"If their presence in the show they were famous for isn't enough to keep their career going, then maybe they need another line of work," Bell said.

But don't say that to Coolio, who donated his combined $75,000 winnings to charity.

"The people who criticize are not giving $50,000 to those kids," Coolio said. With a new album coming out Oct. 15, he said his appearances have not detracted from his musical career. "I'm so far past giving a [expletive] about what people think. It doesn't really matter to me."

But while people debate whether stars degrade themselves by appearing on these shows, everyone agrees they know exactly what they're doing.

"It's always a business deal," Shore said. "We approach them, and work out a deal. We appeal to them in a very honest way."

But do these shows prey on has-beens who have no other way to make a living?

No, Felling says.

"They're not exploitative," he said. "These people have gone beyond being famous for their accomplishments and are now famous for being famous."

Perhaps figure skating bad girl Tonya Harding put it best when she told Entertainment Tonight she was facing Paula Jones in Celebrity Boxing "for fun and publicity -- and of course, the money."

But not everyone is jumping on the has-been bandwagon.

"A lot of people turn these things down," Shore said.

But for most of the stars, it's just their nature to want to be in front of the cameras, said Felling. "They're riding this trend. They want the spotlight."