The Insider.com

Look at these clips from a few of yesterday’s late night performances:

• The Sounds performed their title track "Something to Die For" on "Jimmy Kimmel Live!"

• Far East Movement rocked the house with their latest hit single "Rocketeer" from their album Freewire on "The Late Late Show with Craig Ferguson."

• Los Lonely Boys performed their title track "Rockpango" on "The Tonight Show with Jay Leno."

Lady Gaga celebrated her 25th birthday in style at the Staples Center in Los Angeles Monday night, delivering one of her many empowering speeches before belting out "Born This Way." Watch the video!

Surrounded by a packed arena crowd of her dedicated Little Monsters, Gaga did not disappoint with a parade of outlandish costumes, from a body suit and knee-high boots to a giant red cloak and a see-through nun-inspired costume.

Britney Spears rocked an early morning crowd in San Francisco on Tuesday, performing on ABC's "Good Morning America" and leaking details on a new tour.

"We're going on tour with Enrique Iglesias in June," announced Britney, who performed her hit single "Hold It Against Me" from her new album Femme Fatale.

The pop diva gave a secret performance in Las Vegas over the weekend at Palms Casino Resort's Rain Nightclub. Britney hit the stage twice on March 25 - once in a ticketed event and another at a midnight show that was open to the public.

Femme Fatale drops today.

Hollywood's hottest youngsters promoted the Ocean Pacific Spring/Summer clothing line, doing a photo shoot in Lancaster, California, which - it turns out - might not be as easy as it looks.

The ladies of the OP marketing campaign: Aly Michalka, Kat Graham and Brenda Song suffered the most in the shoot, wearing next to nothing in 50 degree weather.

"At least we're laughing about it," said Michalka.

"We're using body heat to keep ourselves warm," Song added.

The male to female ratio was balanced out with Robert Kardashian, Mark Salling and Chord Overstreet providing the testosterone for the photo shoot.

"I'm definitely the manliest, strongest and the cutest [guy here]," Kardashian joked.

Watch the video to find out why the girls chose to wear their bikinis in their interview with "The Insider."

Eighteen years ago today in 1993, Sir Elton John hosted his first Elton John AIDS Foundation Academy Awards Party following the 65th Academy Awards.

Speaking before the party's kickoff, Sir Elton said, "I thought it would be a good idea to start my own AIDS foundation because it's a cause I feel very passionate about. When you get to my age you have to reinvent yourself and find something else other than your career to devote your energies into, and I thought it would be good for me to do this, to commit to something like this."

Since 1993, the Elton John AIDS Foundation has raised over $220 million dollars to support HIV/AIDS projects around the world.

The new action thriller 'Source Code' explores the concept of time travel and fixing the past, so "The Insider" got the stars of the movie to dish on what they would change about their own past at the movie premiere on Monday.

"I'd like to go back and have eight minutes at my wedding," said Michelle Monaghan, who married Pete White in 2005. "I think I made the mistake of not video taping it."

"I would definitely change my prom dress," Vera Farmiga joked.

'Source Code' follows Colter Stevens (Jake Gyllenhaal), a soldier who finds himself sent to the past with eight minutes to prevent a tragedy on a commuter train in Chicago, and the star of movie suggested that he would use his hypothetical eight minutes of time travel in a similar way as depicted in the film.

"I'm a real big proponent of having regret as a big teacher," said Gyllenhaal. "I'd probably like to recreate minutes that could save a thousand people as opposed to eight minutes of my own."

'Source Code' steamrolls into theaters April 1.

Tom Cruise and Katie Holmes stepped out in L.A. on Monday night for the premiere of Katie's new miniseries, "The Kennedys."

Katie plays beloved First Lady Jackie Kennedy in the ReelzChannel miniseries, and she said taking on such a lauded historical figure was a tall order: "As exciting as it was, it was daunting because she was loved by so many. You walk into a situation trying your best, but everyone has their idea of who she was and so you're never going to please everyone, so once I got kind of past that then I felt free to create this character."

She said that donning the wardrobe of Jackie's iconic style every day was "really a lot of fun" and said that between wardrobe, hair and makeup, "Once you walked out of the trailer, you felt different, because you had been transformed."

Greg Kinnear, who co-stars as former President John F. Kennedy, also stepped out for the premiere of the miniseries, which will debut April 3 on ReelzChannel.

The cable channel picked up the show after it was announced earlier this year that the History Channel had dropped the show. An A&E rep explained to "The Insider," "While the film is produced and acted with the highest quality, after viewing the final product in its totality, we have concluded this dramatic interpretation is not a fit for the History brand. We recognize historical fiction is an important medium for storytelling and commend all the hard work and passion that has gone into the making of the series, but ultimately deem this as the right programming decision for our network."

The Reese Witherspoon honeymoon details -- where the newlyweds were spotted today!

Plus, why second marriages in Hollywood work.

Then, Jillian Michaels' "Biggest Loser" face-off with our Kevin Frazier!

And the kids of "Glee" Backstory. Next "Insider"!

Kirstie Alley may not have completely buried the hatchet! Kirstie accepted George Lopez's apology for making jokes last week implying that she was a pig, but the "Dancing with the Stars" contestant had some choice words for Lopez following her performance on Monday night's show.

"He's a bitch but whatever," Kirstie told Entertainment Tonight. On March 25, Kirstie tweeted, "[George Lopez] I don't need or want your apology...I want your kidney dude..on behalf of your ex and all the women you've insulted...give it back," before publicly accepting the comedian's apology.

In 2005, George Lopez underwent a kidney transplant with his estranged wife Ann as the donor. The couple filed for divorce in 2010.

"My whole kitchen is filled with flowers," Kirstie told "The Insider" correspondent Christina McLarty, revealing how far the late-night host has gone in an attempt to win her approval.

Be sure to watch an all-new "Dancing with the Stars" Tuesday on ABC.

How did your faves rank on the "Dancing with the Stars" scoreboard tonight?

Here's the "Dancing with the Stars" scoreboard for season 12 so far! Judges' scores and viewers votes from the first two weeks of competition will be added together to determine which pair will be eliminated on Tuesday night. Although three contestants scored higher than him this week, Ralph Macchio remains the overall leader. The bottom of the scoreboard remains unchanged as well, with Mike Catherwood holding on to the lowest rank.

Kourtney Kardashian is stepping away from the reality cameras and makes her acting debut on one of TV's most popular soap operas.

The eldest Kardashian is set to appear on "One Life To Live" as Kassandra Kavanaugh alongside show favorite Cristian Vega, played by David Fumero.

Click the video to check out clips from the episode which airs March 28.

After last night's season high ratings, Donald Trump took time to talk about the latest episode of "Celebrity Apprentice" and its surprising influence in the media.

"Well I'm amazed at how much press this is getting," the real estate mogul said. "People are finding the show fascinating, that's why the ratings are so good but I'm amazed at how the press is covering it because they can't get enough of the show."

Donald also spoke on his decision to fire the latest contestant, Dionne Warwick. "She had attitude, she had a lot of things going," Donald affirmed. "Boy she had attitude and the other women on the show really couldn't stand her, they couldn't take her any longer and they really went against her."

When confronted with whether or not the drama will stop on the show, the Donald resounded with a less than subtle hint. "Well what happens in the next four weeks is the most incredible scenes I've ever seen on television or reality television in terms of fights and craziness."

Check out the video to hear more from the Donald and tune into "Celebrity Apprentice" Sundays at 9 p.m. on NBC.