An annual luncheon for Oscar contenders drew 151 of the nominees Monday, among them "The Social Network" star Eisenberg, "The Fighter" co-star Leo and "The Kids Are All Right" co-star Ruffalo.
Other acting nominees on hand included past winners Nicole Kidman, Javier Bardem, Jeff Bridges and Geoffrey Rush, veteran nominees such as Annette Bening, Colin Firth and Natalie Portman and newcomers such as Jennifer Lawrence and Hailee Steinfeld.
Best-actor nominee Eisenberg told reporters before the luncheon that the many Hollywood gatherings leading up to the Feb. 27 Oscars remind him of his early teens.
"I had to go to bar mitzvahs every weekend, and this is like the same feeling," Eisenberg said. "Putting on a suit every weekend to go meet with a lot of Jews."
Leo, considered the favorite to win the supporting-actress Oscar, said she tries to keep up her strength during the awards rush with "water, vitamins. And the excitement of it is pretty much of an energy drink right there."
First-time nominee Ruffalo said he was surprised he earned the Oscar honor given that his role probably was the least showy in the film, whose cast includes Bening and Julianne Moore.
"It's taken me a long time to get here, so I really have been, as a meditation, making myself enjoy the hell out of it every single day," Ruffalo said. "And I love free lunches, man. I came up as a starving, struggling actor, so I'm very grateful for a gift lunch."
Nominees shared a fine meal at the luncheon, whose menu featured appetizers of Indochina-spiced beef with avocado mousse, an entree of Alaskan black cod and a dessert selection that included mini lemon meringue tarts with blueberries and raspberry sorbet in cookie shells.
Talk inevitably touched on what nominees would wear to the Oscars, one of the world's biggest fashion showcases.
Fourteen-year-old Steinfeld, nominated as supporting actress for her debut performance in "True Grit," said that in past years, she watched the ceremony at home "mainly for the red carpet, just to see what everyone's wearing."
Michelle Williams, a best-actress nominee for "Blue Valentine," said she had settled on one pair of shoes that she's been wearing to every event this awards season.
Kidman, nominated as best actress for "Rabbit Hole," joked that her 2-year-old daughter has strong fashion opinions that will be taken into consideration.
"She chooses what she calls pretty dresses," Kidman said. "She has a very strong voice in terms of what I will be wearing on the night of the Oscars. Fingers crossed, guys. I could be wearing a tutu."
Portman, pregnant with her first child and showing a pronounced baby bump, said picking out an Oscar gown is more challenging with an expanding waistline.
"It's certainly all about leaving space for growth," said Portman, the best-actress front-runner for "Black Swan," who lamented that fashion has become such a fixation in awards season. "It is always surprising also that that's become the conversation instead of the movies now. What are you wearing?"
Last year's best-actor recipient for "Crazy Heart," Bridges is competing in the same category this time for "True Grit." Oscar night again pits him against Firth, who was nominated last year for "A Single Man" and now is in the running for best-picture favorite "The King's Speech."
Like most people in Hollywood, Bridges figures this is Firth's year.
"He'll probably take home the trophy this year," Bridges said. "He gives a wonderful performance."
Firth - starring as Queen Elizabeth II's stammering father, King George VI, who reluctantly took the throne in 1936 after his brother abdicated - joked that he sometimes gets royal treatment since the film came out.
"I do get the odd bow, which I put down to either confusion or facetiousness," Firth said.
Others at the lunch included Firth's co-stars, supporting-acting nominees Helena Bonham Carter and Geoffrey Rush, and supporting contenders Amy Adams ("The Fighter"), John Hawkes ("Winter's Bone"), Jeremy Renner ("The Town") and Jacki Weaver ("Animal Kingdom").
James Franco was doing double-duty at the lunch, a best-actor nominee for "127 Hours" and preparing for his gig as co-host of the Oscars with Anne Hathaway.
TV ratings for the Oscars have fallen from their peak decades ago, and the show's producers have been trying to spice up the ceremony in recent years to hook a new generation of fans. Franco mused over criticism that followed the announcement of him and Hathaway, a switch away from older veteran comics as hosts.
"A lot of the reaction was, oh, an obvious ploy by the academy to bring in younger viewers," Franco said. "Yeah! Duh! Is that a bad thing? I mean, how is that a criticism?"