“Given the crisis that we’re in and the hardships that so many people are going through, we can’t allow any idle hands,” Mr. Obama said. “Everybody’s got to be involved. Everybody’s going to have to pitch in. I think the American people are ready for that.”

tens of thousands of citizens arrived here from all corners of the country, traveling to the capital to see the inauguration of the 44th president just before noon on Tuesday, Mr. Obama opened his day by visiting wounded troops at Walter Reed Army Medical Center and concluded it by honoring his former Republican rival, Senator John McCain.

“We will not always agree on everything in the months to come, and we will have our share of arguments and debates,” Mr. Obama said, speaking to a bipartisan audience at one of three banquets he attended on Monday evening. “But let us strive always to find that common ground and to defend together those common ideals, for it is the only way we can meet the very big and very serious challenges that we face right now.”

While contributors flocked to black-tie dinners, other revelers filled the Mall, eager to catch a glimpse of the spot where Mr. Obama will be sworn in. Though Washington became virtually mired in gridlock, there seemed to be more waving flags than blowing horns as people navigated the city’s crowded corridors.

Mr. Obama delivered a few test runs of his Inaugural Address, which advisers said would be about 20 minutes long. The final draft of the speech was largely written by Mr. Obama himself, after he studied several previous addresses that were given at times of great challenge to the nation.

“I’m not going to make a long speech,” Mr. Obama said as he entered Calvin Coolidge High School on Monday afternoon to take part in a community service project. “I’ve got to save my best lines for tomorrow.”

<His appearance a few hours earlier at the Sasha Bruce House, a shelter for homeless teenagers here, allowed Mr. Obama to make good on a promise to become more involved with his new home city, even as he showed his stripes as an ordinary guy in the process. With a paint roller in one hand, he joked, “This is good practice, because I’m moving to a new house tomorrow.”

Deborah Shore, who founded the shelter 34 years ago, said later in a telephone interview, “He painted very well, I might say.” She added: “They have said that they’re going to have a different relationship with the city than has often been, a deeper, closer relationship. I think this is proof of that.”

In his final day in the White House, President Bush was out of the spotlight on Monday. He spent his morning on the telephone calling the leaders of Brazil, Britain, Denmark, France, Germany, Israel, Italy, Japan, Russia and South Korea. Mr. Bush also spoke with Vicente Fox, the former president of Mexico.

A White House spokesman, Gordon Johndroe, said the president had thanked the leaders for their cooperation and hospitality over the years.

In one sign that power in Washington is about to change hands, the White House issued a quick correction on its statement late Monday afternoon about the selection of Alan Lowe, a former National Archives official, as director of Mr. Bush’s as-yet-to-be-built presidential library and museum.

But this was the Jonas Brothers.

First daughters Malia and Sasha got up on stage to dance with the teen rockers Monday night at the first-ever Inaugural Kids Concert, with mom Michelle, Jill Biden and her grandkids in attendance.

Of course, the concert had a serious side, to honor the parents of 4,000 children of military service members in the crowd.

But for Malia, 10, and Sasha, 7, it had to rate as a highlight of the weekend. Earlier, Malia snapped away with her camera as one of her favorites, Miley Cyrus, performed.

For all the star power on stage, even they played second fiddle to the members of the incoming First and Second Families in attendance.

When Corbin Bleu of “High School Musical” fame went into the audience, Sasha and Malia played it cool – shaking his hands but trying to not look too excited. It was mom Michelle who played like the fawning fan, shaking his hand like a star-struck teen.

And the whole family clapped as actor Jamie Foxx went old school, beat boxing to the name of the next president and telling the Obama girls, “You guys oughta be awfully proud of your dad, and so am I.”

Other than that, the concert looked pretty much like what you’d expect when you mix a room full of ‘tweeners with the likes of ubiquitous Disney Channel acts like the Jonas Brothers and Cyrus, along with Bow Wow.

Like a bunch of ‘tweeners screaming their heads off.

In between the music, Obama and Jill Biden spoke directly to military families. “Barack, Malia, Sasha and I are so grateful for the service and sacrifice,” she said. “Our family does join you all in praying for your loved ones.” Obama also urged the youngsters to find ways to serve their country by volunteering.

“We need every American to serve their community, including young people.”

Biden, joined on stage by her grandchildren, said that “military families are true American heroes. Thank you all for what you do for our country every day.”