Tuesday night into Wednesday morning was for girls only as far as Britney Spears was concerned: The singer went out on the town with two female pals for a long round of dinner and dancing.

First stop for Spears and her friends, Alli and Jessica: Dominick's in West Hollywood, for a healthy meal of grilled rare Hawaiian blue fin tuna with lemon pesto and sugar snap peas. According to another diner, "Britney [was] in really good spirits. She was having a fun girls' night out with her pals."

Then the ladies when off to club Les Deux, where the trio – along with Spears's bodyguard – arrived just after 11 p.m. and commandeered "the playpen," in a secluded area of the hotspot.

"Britney was dancing like crazy and in a great mood," an onlooker tells PEOPLE. "She seemed like she was on top of the world and wanted everyone to see her."

The partying continued, and Spears even hopped into the DJ booth at one point.

The star attraction and her gal pals stayed until well after closing, never even bothering to greet Ryan Phillippe (there having a low-key night with Flags of Our Fathers costar Jesse Bradford) or even Rumor Willis (who also stopped in).

Spears & co. finally made their way out into the parking lot by nearly 3 a.m.

Aside from dancing in clubs, Spears is scheduled to perform this weekend in Florida. According to a source, she is booked at the Orlando House of Blues on May 19 and Mansion in Miami on May 20.

The singer recently performed four shows at other House of Blues clubs in Southern California and Las Vegas.

On Wednesday, the singer thanked fans in a message on her Web site, saying that people's "prayers have truly helped me."