WASHINGTON - Short on sleep but with a long to-do list, President Obama walked into the Oval Office at 8:35 a.m. Wednesday for 10 contemplative minutes alone.

Then the change began.

Hours after his whirlwind tour of 10 Inaugural Balls that ended early Wednesday, Obama jumped into Middle East diplomacy, prepared an executive order to close the Guantanamo Bay, Cuba, prison for terror suspects within a year and pressed his plan to withdraw troops from Iraq. Without holding the usual daily news briefing, press secretary Robert Gibbs resorted to written statements and guidance notes to keep reporters on top of his boss' activities.

Obama says oath again

Barely a day after taking the oath of office, Obama did it again. Chief Justice John Roberts, who flubbed his lines in front of a worldwide audience Tuesday, went to the White House and administered the 35-word presidential oath once more. White House counsel Greg Craig said even though he and legal scholars believe that Obama was duly sworn into office on Tuesday, the oath was administered again "out of the abundance of caution because there was one word out of sequence" and because the oath's precise words are specified in the Constitution.

Obama assembled his senior staff in the early afternoon so they could be sworn in as well. He announced a pay freeze for White House staffers who make more than $100,000, a symbolic move reflecting the nation's tight economic times for all Americans. He signed an executive order implementing strict ethics rules for his administration. And he promised to conduct government business in the open and try to honor outside requests for information - in contrast with the Bush administration, which was known for its secrecy.

With first lady Michelle Obama, he attended the National Prayer Service that traditionally follows Inauguration Day and held a midday reception for 200 selected guests at the White House. And while staffers were still figuring out how to log on to their computers, the White House website bore this message: "Change Has Come to America."

"What a moment we're in. What an opportunity we have to change this country," Obama told his staff at their swearing-in ceremony. "The American people are really counting on us. Let's make sure we take advantage of it."

As first days go, it was customarily crazy-busy. On Jan. 21, 1993, President Clinton had trouble getting an open phone line. "It's kind of a wild ride right out of the gate," recalled Dan Bartlett, who was President Bush's communications director.

Behind the usual mayhem, however, was the understanding that amid a major recession, two wars and the threat of terrorism, things are bound to get busier for the Obama administration.

That was signaled by Obama's choice for Treasury secretary, Timothy Geithner, who warned Congress that the $700 billion being spent to rescue financial institutions and the $825 billion Obama is seeking to jump-start the economy will be only a start. "It is going to require much more substantial action ... on a very dramatic scale," Geithner said.

More executive orders are likely, based on Obama's pledges.

Gibbs said the executive order on Guantanamo Bay would be signed today. It's unclear where Obama would send dozens of suspected terrorists who have been held indefinitely at Guantanamo, a facility that has drawn criticism from around the world.

The plan is already drawing fire from Republicans. Sen. Sam Brownback, R-Kan., introduced legislation Wednesday that would require Obama to give Congress a 90-day notice before moving to close the prison run by the U.S. military. "We cannot afford to make snap decisions about detainee policy," he said.

Obama also has pledged to sign orders banning harsh interrogation techniques that have been likened to torture by critics, restoring U.S. funds for overseas family planning groups that offer abortions, and ending the ban on federal funding of embryonic stem cell research.

Many of his actions were breaks from the policies of Bush, who left office with a 61% disapproval rating in the most recent USA TODAY/Gallup Poll. In the past half-century, only Richard Nixon had a higher rate of disapproval upon leaving office.

Obama's message is that "we have lost our way, and my way is the way back," said Yale University political science professor Stephen Skowronek. "That's a very powerful message."

Meetings on economy, Iraq

In church Wednesday morning, Obama got several reminders of the power - and expectations - he now confronts as president. As several thousand of the nation's leaders entered Washington National Cathedral, the Children of the Gospel Choir of Washington sang Luther Vandross' A Brand New Day

Obama wasted no time reaching out to the world. He called Prime Minister Ehud Olmert of Israel, President Mahmoud Abbas of the Palestinian Authority, President Hosni Mubarak of Egypt and King Abdullah II of Jordan, telling them his administration would begin addressing the long-running conflicts among Israelis, Arabs and Palestinians.

Obama expressed "his commitment to active engagement in pursuit of Arab-Israeli peace from the beginning of his term," Gibbs said. In his first comments on the conflict between Israel and Hamas militants in Gaza, Obama said the USA will work to stop arms smuggling to Hamas fighters and help rebuilding efforts for Palestinians in Gaza.

The calls were "pro forma," said Aaron David Miller, a Middle East expert at the Woodrow Wilson International Center for Scholars. He said Obama soon would appoint former Senate majority leader George Mitchell as a special envoy to the Middle East to work with newly confirmed Secretary of State Hillary Rodham Clinton, which would be "the clearest indication that Obama is going to be serious over time on the Arab-Israeli issue."

In the late afternoon, Obama held his first meeting in the White House Situation Room, which features special sensors to block eavesdropping. The topic was Iraq, from which Obama wants to extract combat troops in 16 months. Assembled around him were Defense Secretary Robert Gates, national security adviser James Jones, Joint Chiefs of Staff Chairman Michael Mullen and Gen. David Petraeus, who heads the U.S. Central Command with authority over the Middle East. Gen. Ray Odierno, commander of the U.S. forces in Iraq, joined the meeting from Iraq via video conference.

"I asked the military leadership to engage in additional planning necessary to execute a responsible military drawdown from Iraq," Obama said in a statement.

On the domestic front, Obama got a briefing on the progress of his $825 billion economic stimulus package from his top economic advisers, including Lawrence Summers and White House budget director Peter Orszag.

Geithner, who will lead the economic team if he is confirmed, appeared before the Senate Finance Committee, where he was questioned about his failure to pay Social Security taxes during four years of employment with the International Monetary Fund. He paid more than $42,000 in back taxes and interest.

Geithner told lawmakers that Obama will speak to Congress in the next few weeks on his economic plan, including efforts to address the housing crisis and limits on consumer credit. "We're going to have to do more to make sure institutions at the core of our system are strong enough that they can lend," he said.

Frozen pay and ethics rules

The major initiatives Obama announced Wednesday were administrative. He froze the pay of senior White House staff members who make more than $100,000 a year for the duration of the economic crisis, without elaborating on how long he thought that would be.

The move affects about 100 employees. It doesn't affect Obama's own $400,000 salary, which is set by Congress. The Constitution says a president's salary cannot rise while he is in office.

After vowing in his campaign that special interests would not have undue sway in his administration, he imposed ethics rules that he said mark "a clean break from business as usual."

Lobbyists who take administration jobs will be barred from working on matters on which they tried to exert influence or in the agencies they lobbied during the previous two years. People who leave the administration are prohibited from lobbying their former government colleagues for the life of the administration. During the Bush years, the maximum cooling-off period had been two years. Obama also banned appointees from accepting lobbyists' gifts, such as meals, travel and lodging.

The previous rule on gifts barred executive branch employees from accepting gifts from people doing business with the agency for which they worked. But there was no blanket prohibition on gifts from lobbyists.

Obama said his goal is "to close the revolving door that lets lobbyists ... use their time in public service as a way to promote their own interests over the interests of the American people."

Meredith McGehee, policy director of the Campaign Legal Center, praised Obama's effort to restrict former government workers from lobbying. But she said federal legislation is needed to make the ban permanent, so that it cannot change from one administration to the next.

President Clinton signed an executive order when he took office in 1993 that barred senior government officials from lobbying their former government colleagues for five years. He revoked it in December 2000, less than a month before leaving office, freeing his aides from the post-employment restrictions.

'Too much secrecy in this city'

Obama also issued directives designed to maintain an open government. "For a long time now, there's been too much secrecy in this city," he said.

Shortly after the 9/11 attacks, the Bush Justice Department issued a memo telling agencies that as long as they acted within the law, they could refuse to release records under the 42-year-old Freedom of Information Act.

"That era is now over," Obama declared. "Starting today, every agency and department should know that this administration stands on the side not of those who seek to withhold information, but those who seek to make it known."

Melanie Sloan, executive director of the liberal-leaning watchdog group Citizens for Responsibility and Ethics in Washington, said Obama's decision to issue the directive "signals that transparency is more than a campaign promise." Her group battled the Bush administration in court over access to Secret Service visitor logs, missing White House e-mails and other records.

Obama also pledged to make more of his own records available. "Transparency and the rule of law will be touchstones of this presidency," he said.

Meet the new boss

One of Obama's first moves Wednesday was to read the note left by Bush in an envelope marked "To #44, From #43." The passing of a note from outgoing to incoming president is a long-standing tradition, but Obama didn't have much time to dwell on it.

Ten minutes after he arrived in the Oval Office, in walked chief of staff Rahm Emanuel. Michelle Obama followed about a half-hour later, and the Obamas posed for a photo. Among the day's other highlights:

-At the multidenominational prayer service, Sharon Watkins, head of the Protestant Disciples of Christ Church, was the first woman to deliver the post-inauguration sermon. "With your inauguration, Mr. President, the flame of America's promise burns just a little brighter for every child in this land," she said.

-At the staff's swearing-in, in the Eisenhower Executive Office Building next to the White House, staffers rose to their feet - an honor reserved for presidents. "I'm still getting used to that," Obama said to laughter.

-At the White House reception, to which 200 people won passes on a first-come, first-served basis through the Internet, Tracie Jones of Bessemer, Ala., was ecstatic. She'd failed to score tickets to Tuesday's swearing-in or Inaugural Balls.

Greeting the president and first lady on the receiving line in the Blue Room, she told Obama he was "beautiful," then thought better of it. "I mean, first lady, you're beautiful!" Jones said.

Contributing: Barbara Hagenbaugh, Joan Biskupic, and the Associated Press