(Cover) - EN Showbiz - Nicole Richie worked hard on her dance moves in preparation for Britney Spears' Los Angeles concert last night.

Reality star Nicole was just one of many big names to attend Britney's Femme Fatale Tour at the city's Staples Center venue, joining celebrities including Paris Hilton and Kim Kardashian.

Nicole is a huge fan of Britney's pop hits, and yesterday posted a clip of herself competing in a dance-off with a pal to the sounds of the singer's 2001 smash I'm a Slave 4 U.

"In honour of my queen, @BritneySpears - Can't wait to dance tonight!" read a message accompanying the video on social-networking site Twitter.

Britney has been receiving rave reviews for the tour so far, which kicked off last week in Sacramento, California. Reality television star Kim was quick to add to the praise after watching the performance last night, urging her followers on Twitter to catch the singer in action.

"Seriously u guys, tonight @britneyspears just had the best concert ever! She killed it in LA! Proud of u doll ;-) must see concert! (sic)," gushed Kim.

Meanwhile, socialite Paris went to the concert with mom Kathy and sister Nicky, and was particularly impressed with the pop star's outfit choices. Paris was eager to find out who had been behind Britney's seductive stage costumes, which were in fact the handiwork of costume designer Zaldy Goco and include plenty of figure-hugging and sequin-adorned pieces.

"Loves it! @BritneySpears performing @Rihanna's song S&M! Her outfits are amazing! Who did the costume design for her tour? Love! (sic)," wrote Paris on her Twitter page. (C) Cover Media