On Friday, July 3, business was booming at Savanna’s restaurant in Southampton—a favorite of effusive Real Housewife Ramona Singer. “The people that are running it are from T-Bar in the city, which I love,” she said. “The food, just so everybody knows, is great food now, and great service. Because that was always the killer. People would want to go there, but—bad food, bad service. And now the food is great and so is the service. I’m serious!” O.K.!

Meanwhile, on Main Street in East Hampton, Walter Struble, the manager at Della Femina’s, said that Friday was the busiest he thinks the restaurant has ever been. “It was quite surprising because of the state of this economy, but because of the wonderful weather, everyone was very positive and energetic.” Weather anchor Sam Champion made an appearance, along with a Scarlett Johansson look-alike. By the end of the night, employees decided the comely customer was not, in fact, the actress. “She looked identical to her, though!” Mr. Struble stressed.

Guests dining at the Blue Parrot in East Hampton the next night, meanwhile, were surprised with a concert by Jon Bon Jovi. The singer came to the restaurant with his wife, Dorothea Hurley, and performed “Who Says You Can’t Go Home?” “Free Bird” and “Dead or Alive.” Actress Renée Zellweger was there with author Kristen Gore. Democratic Leadership Council chair Harold Ford came to the restaurant for the second time that weekend, after dining with hip-hop mogul Russell Simmons the night before. Former Mayor Rudy Giuliani came for dinner at the restaurant on Sunday night.

Just a couple miles away, at Georgica on Wainscott Road, executive chef Robert Hesse from the show Hell’s Kitchen said that the restaurant served 600 to 700 covers on Friday and Saturday night, compared to 400 to 500 every other weekend. Actors AnnaLynne McCord and Kellan Lutz showed up for dinner, along with Rolling Stone daughter Alexandra Richards and more Real Housewives. “It was packed. The scene was nuts!” Chef Hesse said.

The next morning, Ms. Richards drove up to the Surf Lodge in Montauk in her new Audi, got her makeup done by Maybelline and put on her Tracy Feith bikini. While Ms. Richards DJ’d a selection of reggae music, a huge crowd stood on the deck, including some of her best friends from high school in Weston, Conn.

Designer Calvin Klein’s former wife Kelly stopped by the Lodge on the Fourth, and 300 star Gerard Butler partied all weekend long at the bar. Ad man Jerry Della Femina also made an appearance.

At Day and Night Beach Club in Southampton, co-owner Derek Koch reported that one customer spent $45,000 in a single visit. “When I looked at his bill, I was like, ‘Oh my God!’” he said. Another guy bought every single bottle of Champagne. Day and Night is known for parties that start at noon and end around 8:30 p.m.; Mr. Koch said that on Saturday he was in bed by 10:30. “I mean, I did have to wake up the next morning and do it all over again! It was an amazing turnout. We had around 700 people. It was our biggest weekend, ever.”

Spending was big, too, at Dune Nightclub’s Axe Lounge in Southampton, where one customer dropped around $30,000 dollars on the Fourth, said Mike Heller, president of Talent Resources, which deals with all of the celebrities that go through the nightclub. “Towards the end of the night we ran out of Cristal!” he said.

DJ Vice flew out from the West Coast, “did a whole tribute about Michael Jackson, and, you know, talked about how it’s America’s birthday, blah, blah, blah,” Mr. Heller said, adding, in some wonderment: “There were bottles flowing, sparklers all night and bottles of Champagne! Where’s all the money coming from?”

Dune also enjoyed a huge stampede after the nearby Pink Elephant, already wounded by bankruptcy woes, was closed down to a carbon monoxide scare.

Security was tight, meanwhile, at the Social Life Estate in Watermill, which held only 150 people. Publicist Kristian Laliberte described the atmosphere as being “very young Hollywood meets Manhattan art scene with an East End twist.”

Socialite Lydia Hearst, the cover girl of Social Life Magazine this month, was supposed to host the event along with Mr. Lutz, but was stuck at home with gallstones, Mr. Laliberte said.

The theme of the party was “Great Gatsby,” and while many guests donned borrowed couture, socialite Minnie Mortimer wore a blue-and-white-striped T-shirt dress of her own design.

Fashion designer Ashleigh Verrier was also wearing her own creation: a silvery-white camisole-skirt combo. “It was a really nice crowd,” she said of the event later. “It was intimate. Enough people, but at the same time a level of it being not too crowded.”

Perhaps lulled by the sense of intimacy, actor Nick Stahl fell asleep in the pantry at some point during the evening, said a source.

Ms. McCord was also drowsy. At the end of the party, Mr. Lutz drove her to the Axe Lounge, where another source said she hung out in the car, taking a nap, while Mr. Lutz went back and forth inside the club and back to the car. “They looked very coupley, I guess,” said the source. “Towards the middle of the night, she left the car and came out with him. She was just chilling in the car.”

For the rest of the night, Ms. McCord drank from water bottles and sat at the table, “unlike Lindsey Lohan! When she was here, she was also drinking from a water bottle,” said a different source at the Axe. “But she was dancing all night.”

Not everyone was in the Hamptons, of course, though it felt that way at times. Designer Marc Jacobs and fiancé Lorenzo Martone were rumored to be relaxing in the Berkshires over the holiday weekend, and socialite Lauren Santo Domingo flew to Brittany, France, for a wedding. “Not very patriotic, I know!” she said.