It seems just about everyone in Hollywood wants to save the world these days.

Celebrities are looking for charities to represent, and charities are looking for celebrities to represent them. But is it really worth it to have a star supporting your cause when you're forced to deal with the diva demands, paparazzi penetration and personal problems that often accompany a famous face?

“Charities, of course, want big names to be their spokespeople,” said Roger Cook, director of public relations for The Children’s Miracle Network, which is dedicated to saving and improving the lives of children by raising funds for children’s hospitals across North America. “But the reality is that big names come with baggage.”

For example, Mothers Against Drunk Driving had every reason to be hopping MADD late last year when their spokesgirl, Miss Teen USA Katie Blair, was caught carousing with her sash sister, former Miss USA Tara Conner, and drinking while underage in New York nightclubs.

"In the past, MADD has teamed with Miss Teen USA to raise awareness about the serious and often deadly consequences of underage drinking," Heidi Castle, a spokeswoman for Mothers Against Drink Driving, said in a statement at the time. "However, we do not feel, at this time, that Ms. Blair can be an effective spokesperson on underage drinking and will not ask her to represent MADD in future initiatives."

Paris Hilton, meanwhile, reportedly promised to give $250,000 to an Australian charity, Paradise Kids, and to organize a fundraising concert in support of seriously ill youngsters.

“It makes me feel good and it helps other people,” Hilton explained to the paparazzi at the time.

But that was over two years ago, and the Hilton heiress hasn’t been back in contact with the organization. According to the charity’s co-founder, Rev. Dr. Ian Mayor, Hilton was gone as son as the cameras were.

Mayor told Australia’s Courier Mail newspaper that because Hilton made a public vow to raise $250,000 for the charity, it has hurt their fundraising efforts. He claimed that no one thinks the charity needs money, since Hilton is supposedly helping them, and his efforts to contact the Boulevard blonde have been barren.

Then there's the issue of paying spokespeople. Last year, Hilton was said to have accepted $200,000 just to show up at an undisclosed charity event in Cannes.

“All I had to do was wave like the Queen of England,” the New York Post quoted her as saying.

Cook finds this sort of exchange tasteless.

“It’s completely inappropriate to pay spokespeople,” he said. “Of course we cover all their expenses, but we’re looking for celebs who want to make charity work a part of who they are without the need for financial incentives. But you’re always going to come across a special few who feel more entitled than others.”

Calls to Hilton's publicist were not returned

Meanwhile, Cindy Crawford left fundraisers fuming in 2005 over claims she demanded $126,000 to appear at an event for Romanian leukemia charity Valente Umane, including a private jet and first-class pampering.

While a rep for Crawford declined to comment on the claims, the supermodel is currently helping to publicize the "Strength for Caring Program" that offers assistance to caregivers and families of cancer patients.

Jennifer Lopez has also been known for diva demands.

For her 2001 cameo in the “What’s Going On” production to raise funds for the Global AIDS Alliance and the September 11th Fund of the United Way, Lopez demanded Evian water at room temperature, nine different types of tropical fruit and a white room with white flowers, white drapes, white candles, white couches and white tables, according to the artist rider obtained by The Smoking Gun.

Last month, rapper Snoop Dogg was paid a negotiated appearance fee of $150,000 to perform at the Pussycat Dolls concert at Cipriani Wall Street in New York to benefit UNICEF, the New York Post reported.

He also insisted that 10 members of his personal posse be flown over first-class, and at the last minute almost didn’t attend the concert, as his dressing room wasn’t decked out with an Xbox for playing video games.

“We finally found someone who lent us their kids’ Xbox,” an insider told Page Six.

According to the paper, Snoop and his sidekicks were an hour late making it to the stage, which meant that the Pussycat Dolls (who were paid $300,000 to perform) were forced to speak, and consequently thanked "Unicel" instead of UNICEF.

“The idea that organizations pay and pamper these already rich people is disgraceful,” said Mia Logan, a New York mother whose 3-year-old daughter is suffering from a severe heart condition.

“If stars need to benefit financially, then it’s obvious they have no interest in the cause. Just think how many lives could be saved with that money instead.”

Snoop’s spokeswoman, Tracey Nguyen, wouldn't comment on the UNICEF controversy, but said the rapper founded and funds his own football league to provide 2,000 at-risk American youths an affordable way to play the game.

Along with the dilemmas of dollars and divas, some charities associated with celebrities have the misfortune of their messages being hidden among the hype.

“It is often a case of the bigger the celebrity, the more the media just wants to talk about their life and career,” said Cook. “And the charity gets lost in the story.”

Evidence of this argument can be found in Madonna’s recent trip to a Malawian orphanage. The fact that the superstar was visiting homeless children was sidelined by the chaos of kids pelting the paparazzi cars with stones to keep them away and the intense speculation that Madonna could be adopting again.

So is a star smile worth the stress for charities?

Rachel Weingarten, president of GTK Market Group, which creates partnerships between organizations and high-profile ambassadors, says it's a Catch-22.

“The world of fundraising is a tough business and has to be funded,” she said. “But having the wrong name attached to your cause can be very detrimental.”

And even if the publicity happens to be problem-free, some starry spokesmen may only be at it for a personal plug, she added.

“A celebrity may benefit from tax breaks by contributing to a charity or by creating their own charitable initiative,” warned Weingarten. “It also works in their favor by giving them the chance to repair a tarnished image by appearing a do-gooder and concerned citizen.”

Nevertheless, there are a lot of A-listers who really do seem passionate about their charity work.

Halle Berry supports the Jenesse Center, a shelter in downtown Los Angeles for domestic violence survivors and their children. Nicolas Cage recently donated $2 million to establish a fund to help former child soldiers, which will include support for rehabilitation shelters, medical services and psychological and reintegration services.

And since colorectal cancer claimed the life of her husband, Katie Couric, as co-founder of the National Colorectal Cancer Research Alliance, has dedicated her life to making sure people stay informed about the disease.

Meanwhile, Brad Pitt, Angelina Jolie, Oprah Winfrey, Bono, George Clooney, Nicole Kidman, Madonna and more are trying to put a stop to suffering in African nations.

So what's the secret to finding the right celeb? Make sure they undergo ample screening before signing on, experts say.

“Generally, when a charity seeks to attract a high-profile partner, they will carefully vet the person and study their background, strengths and relationships,” said Weingarten.

“The most successful partnerships evolve when the spokesperson has a personal experience or a strong passion to play a powerful part in helping others."