He began his day with a visit to Walter Reed Army Medical Center, where he visited 14 veterans injured in Iraq and Afghanistan.

Then his motorcade headed for the Sasha Bruce House, a facility for homeless teens, where he grabbed a paint roller and helped volunteers who were fixing up rooms.

"We can't allow any idle hands," he said. "Everybody's got to be involved."

Later, Obama joined his wife at a high school where they greeted 300 volunteers who were writing letters to U.S. troops and doing other volunteer work.

The president-elect thanked them and said, "If we're waiting for somebody else to do something, it never gets done. We're going to have to take responsibility, all of us. This is not just a one-day affair."

Referring to his imminent new job, he said, "I am making a commitment to you as your next president that we are going to make government work."

Obama's public events recalled his time as a community service organizer in Chicago, in the years before he entered politics. An Illinois state senator a mere four years ago, he won election to the U.S. Senate in 2004 and announced his candidacy for the White House in early 2007.

A party atmosphere took hold on the National Mall. As light snow fell intermittently, small crowds gathered around large-screen televisions showing reruns of Sunday afternoon's concert featuring a star-studded cast. Several blocks from where Obama will take the oath of office, the Boy's Choir of Kenya gave an impromptu performance for anyone who happened to be nearby.

"Mission Accomplished," read the headline on a souvenir magazine that bore the picture of Obama and his wife.

Two wreaths materialized at the site of a future memorial to King on the Mall in an area on the Tidal Basin between the Jefferson Memorial and Lincoln Memorial. "The cadence and syntax of Obama, it comes directly from Dr. King," said Kirk Moses, a retired high school teacher as others in his group took pictures of the bronze plaque marking the spot for the future memorial.

Bush spokeswoman Dana Perino said Defense Secretary Robert Gates had been designated to stay away from Tuesday's inaugural festivities "in order to ensure continuity of government." By custom, one government official stays away when others in the line of presidential succession attend public events. Gates has been tapped to remain in his post by Obama.