Britney Spears stepped out with Johnny Knoxville and the rest of the guys of Jackass to shoot a bit in LA today. The sketch aired during tonight's episode of Jimmy Kimmel Live, where Britney also performed her three song series in new costumes — we were in the audience so check out some pictures on our Twitter! Johnny was one of Jimmy's guests this evening and during his interview, he joked that Britney actually made a cameo in Jackass 3D that didn't make it into the movie. Jimmy then showed the spoof clip, which had Britney participating in one of their very gross port-a-potty stunts. She wasn't afraid to get a little dirty for a laugh, but was all cleaned up when she took the stage. She reprised the sexy moves she debuted in Vegas and SF over the weekend, and it's even more exciting since Femme Fatale was finally released today! Earlier this morning during her Good Morning America show Britney announced plans for a US tour this Summer with Enrique Iglesias, though, unfortunately, he already pulled out due to the high production costs of moving her elaborate sets.

Courteney Cox slipped on a bikini and hit the beach in St. Barts today. She was joined by her Cougar Town costar Josh Hopkins and her daughter, Coco, for a fun day near the water after stepping out in the sand with a friend earlier in the day. The tropical vacation comes after Courteney and Coco spent time together with Josh while filming the series in Hawaii earlier this month. They also shared the sun with Courteney's possible real-life flame, Brian Van Holt, during their stay on the islands. Courteney and Brian may or may not be an item, since she seems to still be in limbo with her estranged husband, David Arquette. She shared sweet words about him while doing press for Scream 4, which has most of you convinced things are not over between the two. They'll be in the spotlight together again soon when they hit the red carpet to show off their thriller, and starting tomorrow we'll need your help choosing which lucky I'm a Huge Fan finalist will get to interview them at the premiere!

Sofia Vergara was back on the beach filming her Diet Pepsi commercial in Venice this afternoon. She donned the one-piece to shoot with David Beckham yesterday, but this time Sofia showed off even more skin by revealing the skimpy backside of her suit. Sofia's been bouncing around from one set to another lately, getting into character for her big-screen project New Year's Eve and also showing up for the Modern Family cameras. It looks like she's enjoying her time at her current ocean-side location, and the star even indulged in a sweet treat between takes.