Paris Hilton & Britney Spears(R)

Pop singer Britney Spears is back in action, with her post-breakup tour taking her to Las Vegas where she hit the town with Mario Lopez and Paris Hilton.

After stops in New York and Kentwood, La., Spears and her former manager Larry Rudolph arrived in Las Vegas where they kept a very low profile until hitting the town Friday, reported People magazine.

Spears was spotted in the Palms Casino Resort wearing a pink wig and big, dark sunglasses while talking to the casino's owner George Maloof. Spears also went into the Palms' recording studio with producer Lukasz Gottwald to mix tracks on her new album.

"She looks and sounds great," a source told People. "Her voice never sounded better. She's having fun."

Spears was also introduced to Lopez and they headed to the Moon Nightclub with a small group of friends. The singer later met up with Hilton at Tryst in the Venetian, People said.