By midnight, the stage at the Western States Inauguration Ball had seen more canoodling couples than a small-town lovers' lane. At around 11 p.m., Vice President Joe Biden and wife Jill embraced in a ceremonial inaugural dance. Near midnight, President Barack Obama and first lady Michelle grooved together on the same floor. But hours earlier, in a surprise guest appearance, Jennifer Lopez cuddled with hubby Marc Anthony on that very same stage.

Tuesday night's celebrations were divided by geographic region, and this party was for all things West - from America's rugged wilderness to chichi California. Hollywood types like director Ron Howard shared the floor with Montana cowboys. One rancher, Brett DeBruycker, was a president himself - of the Montana Cattleman's Association. "There's more people in this room than in my entire state," he laughed.

Held in the cavernous basement of the Washington Convention Center, the ball didn't have much to offer guests by way of entertainment for the long hours leading up to the arrivals of the presidential couples. A shimmying cover band played the hits, lines for cocktails stretched for miles, and some deflated guests slumped on the floor in their voluminous ball gowns.

To the rescue came Anthony, the star performer of the night. Anthony pumped out Latin music, telling the crowd repeatedly, "You know, it's OK to dance." He took a breather with the slow song "You Sang to Me." "I wrote this song for Jennifer about 10 years ago," he said. "It didn't work back then, but eventually ... she got the point."

To prove that point, Anthony's muse herself stunned the crowd when she unexpectedly strutted onstage, wearing a white chiffon asymmetrical dress (a bling-free version of Michelle Obama's dazzling wonder). Crushing rumors about their marriage being on the rocks, Lopez and her husband salsa-ed together during a duet in Spanish and closed the number with a kiss. As the crowd cheered his wife, Anthony couldn't help but gush: "Man, she's cute."

Another gusher was Tyra Banks, who alternately poured out her love for Barack Obama and Nicole Miller, who designed her brown evening gown "from scratch." Obama's decision to appear on her talk show last year personally affected the model, she said. "I was nervous. He validated me as a journalist," she said. "He made me feel proud of my accomplishments."

After the Latin interlude, the army of ball-goers stood at attention for hours, waiting for the brief appearance of the Bidens and Obamas, who were scheduled to pop into each of the 10 official balls that evening. In the packed crowd, more than four people collapsed and at least two had to be removed on a stretcher. A young law student who fainted begged paramedics not to carry her out on a gurney: "It will be so embarrassing!"

Despite some hairy moments, and the dreary tedium of waiting, the appearance of Joe and flame-red-clad Jill Biden got the crowd back on its feet again. Biden's humble comment that "now you're gonna see how I can't dance" didn't stop the thousands of onlookers from cheering as the vice-presidential couple swayed in each other's arms. But it was nothing compared to the response Obama and his wife garnered when they twirled and hugged on the dance floor. Obama's simple "hello" was met with a deafening response, and when his hands lowered to the first lady's hips, oohs and aahs filled the air.

Though he stepped on her train, Obama may have made it up to his wife with his closing comments. Michelle, he said, "Does everything I do, but she does it in heels." With a wave, he turned with one last message to the audience: "Let's go change America."