1 Said: "So help me God." The phrase is not required by the constitution, so it's arguable that he, Barack Obama, was president by the time he said it, making these his first words in office.

2 Delivered a 17-minute inauguration address, telling the crowds it was time to "pick ourselves up, dust ourselves off and begin again the work of remaking America".

3 Invoked biggest cheer of the day from the 2 million-plus crowd with the words: "Today I say to you that the challenges we face are real. They are serious and they are many ... But know this, America - they will be met."

4 Then the words: "We reject as false the choice between our safety and our ideals." George Bush, sitting to his left, looks decidedly uncomfortable.

5 With his wife, Michelle, escorted George and Laura Bush to the waiting helicopter, where the two men hugged before the former president began his journey home to Texas.

6 As the helicopter disappeared into clear skies, Obama now had Washington, and the United States, all to himself. His relief was palpable.

7 Inside the Capitol building, signed his first documents as president, including cabinet nominations.

8 "I'm a lefty. Get used to it," he said, as he signed. Obama is the fourth southpaw, or left-handed, president out of the past five (Dubya is right-handed).

9 Signed a proclamation declaring 20 January 2009 a national day of renewal and reconciliation.

10 Completed the signing session, looking wistfully at the object in his left hand. "I was told not to swipe the pen," he said.

11 Attended a lunch with congressional leaders, where he dined on a menu from Lincoln's day: pheasant, duck and apple cake served on replica Lincoln White House china.

12 Addressed the assembled crowd, minus Ted Kennedy, who was removed on a stretcher with medical difficulties.

13 Entered his limousine, nicknamed The Beast, to begin the parade down Pennsylvania Avenue to his new home at number 1600.

14 The armour-plated Beast has tinted windows, but through them Obama could be seen clearly practising his military salute.

15 Walked two stretches of the 1.7-mile route, waving at the crowds lining the street.

16 Briefly entered the White House with his family - the Obamas' first moments in their new home.

17 As he entered the North Porticoe into the central entrance, he passed a portrait of the elder George Bush on his left and Bill Clinton on the right. Straight ahead of him, above the door to the Blue Room, was the seal of the US president. His seal.

18 Took his position in the reviewing stand outside the White House, to watch 40 bands and other groups parade past, including the World Famous Lawn Rangers from Illinois, who pushed decorated lawn mowers.

19 Tried out that salute, as cadets marched by. Not bad, though he needs to keep his hand straight.

20 Instructed military prosecutors to seek a 120-day halt to legal proceedings involving detainees at Guantánamo Bay.

21 Issued an order instructing government agencies to halt all pending regulations signed by Bush - a way of combating efforts by the outgoing administration to force through last-minute changes without congressional approval.

22 Danced with Michelle to Beyonce's rendition of At Last, by Etta James, as the opening dance of the Neighbourhood Ball.

23 Appeared to step on the train of Michelle's custom-designed gown by Jason Wu, but otherwise showed himself to be a decent dancer.

24 Gave a brief interview to ABC News, whose reporter said: "Mr President - sounds good, doesn't it?" "It's got a certain ring to it," he replied.

25 Danced and spoke again at the Home State Ball, for Illinois and Hawaii.

26 A quick transfer to the Commander-in-Chief ball, with many military attendees, and a satellite link to war zones. Obama danced with Army Sergeant Margaret Herrera of Texas, who burst into tears.

27 Visited the Youth Ball, for people aged between 18 and 35.

28 Visited the Home State Ball for Delaware and Pennsylvania, in honour of Joe Biden, his vice-president.

29 Briefly visited the Mid-Atlantic Ball.

30 ... And the Western Ball ...

31 ... And the Midwestern Ball ...

32 ... And the Southern Ball ...

33 ... And the Eastern Ball. The couple looked increasingly exhausted as the evening progressed, and sped up their appearances, ending the night ahead of schedule.

34 Back to White House at 12.55am to spend his first night there.

35 The Obamas slept in the master bedroom in the private residence on the first floor of the White House. Their daughters, Malia and Sasha, who were treated to a treasure hunt by White House staff on their first evening culminating with a surprise visit by their favourite music act the Jonas Brothers, slept in bedrooms over the corridor once occupied by Amy Carter, Tricia Nixon, Luci Johnson and Caroline Kennedy.

36 Four hours of sleep and he was up and at it on his first full day. Lights were reported in the private residence at 5am.

37 Obama probably squeezed in a visit to the exercise room on the second floor. He has daily 45-minute gym sessions.

38 Spent his first 10 minutes alone in the Oval Office.

39 Got to sit for the first time behind the Resolute desk, a gift from Queen Victoria to America in 1880.

40 Read the letter that Bush had left for him, according to tradition, in the top drawer of the desk, marked: "To #44, From #43". Its contents have not been revealed.

41 Discussed the day's events with his chief of staff, Rahm Emanuel. It's their first Oval Office meeting.

42 Posed for pictures taken by his personal White House photographer of him and Emanuel in deep discussion. Press photographers later expressed their anger that they weren't invited to capture the moment.

43 Briefly spoke with his wife, Michelle, in the Oval Office.

44 Attended morning-after post-inauguration service with his family, the Bidens, and the Clintons, at the Washington National Cathedral.

45 Laughed when Rev Samuel Lloyd proclaimed: "This is their first full day on the job and the best way we can imagine to begin is by praying for them."

46 Listened, with head bowed, to the first sermon at a president's inaugural church service delivered by Rev Sharon Watkins.

47 Telephoned the president of the Palestinian Authority, Mahmoud Abbas - according to Abbas's spokesman, the call was Obama's first to a foreign leader.

48 Phoned the Israeli prime minister, Ehud Olmert.

49 Phoned King Abdullah of Jordan.

50 Phoned Egypt's president, Hosni Mubarak. The Middle Eastern calls, Obama's press spokesman said, were intended "to communicate his commitment to active engagement in pursuit of Arab-Israeli peace from the beginning of his term".

51 Issued executive order limiting the powers of former presidents and vice-presidents to block the release of sensitive records of their time in the White House. It would allow the administration to approve release of former vice-president Dick Cheney's records, among others, against his objections.

52 Issued instruction to government agencies to be more responsive to freedom of information requests.

53 Announced a tightening of rules on ex-lobbyists working in government.

54 Announced a pay freeze for his staff earning $100,000 (£73,000) or more. "Families are tightening their belts, and so should Washington," he said.

55 Witnessed the swearing-in of about 50 senior members of White House staff.

56 Told his top team that "transparency and the rule of law will be the touchstones of this presidency".

57 Biden made a joke about Chief Justice Roberts's flubbing of the presidential oath as he prepared to lead the swearing in. Obama did not look amused. Was this one transparency too far?

58 Personally greeted each of the newly sworn-in staff.

59 Obama hosted an "open house" in the White House for 200 people who had been granted tickets on a first-come, first-served basis; some were in tears.

60 "Welcome, enjoy yourself," the president told one young man. "Roam around. Don't break anything."

61 Met the joint chiefs of staff and other members of his national security team to discuss Iraq and Afghanistan. His first chance to check out the wizardry in the Situation Room, with its screens receiving satellite images from around the world and its banks of incoming top-secret messages.

62 Met economic advisors to discuss his stimulus package, which could be worth $900bn.

63 Re-swore the oath of office in the White House Map Room out of an "abundance of caution". Or alternatively as a way of killing off the storm of right-wing agitprop that has been tearing through the internet suggesting that the first botched attempt at the oath means Obama is not rightfully president.

64 This time they got it right. Roberts asked "Are you ready to take the oath?" Obama replied: "I am, and we're going to do it very slowly."

65 "We decided it was so much fun." Obama joked to reporters after the event. "The bad news ... is there's 12 more balls."

66 Ate dinner with his family at the White House on Wednesday evening in the private dining room on the first floor.

67 Was waited upon by the 95-strong White House staff. Barack and Michelle will not have to make their own bed for as long as they are in the mansion, though Malia and Sasha will, at their mother's insistence.

68 Gave a speech at a Wednesday night Thank You Ball for campaign workers at the Washington DC Armoury. "You guys dress a lot sharper than you did in Iowa!" he told the crowd.

69 Walked up and down the rope line shaking campaign workers' hands - officially, the final act of the inauguration celebrations.

70 On Thursday morning, said goodbye to his daughters, Sasha and Malia, who were returning to Washington's Sidwell Friends school after two days off for the inauguration.

71 Back to the gym for likely work-out.

72 Absorbed the news that the specially commissioned piece of music by John Williams played "live" at his inauguration by a quartet of world-class musicians had in fact been recorded two days' previously.

73 Released statement on the 36th anniversary of the landmark Roe v Wade supreme court judgment, reaffirming his commitment to protecting abortion rights.

74 To applause, signed executive order requiring the closure of the military prison at Guantánamo within one year.

75 Obama said: "The message we are sending around the world is that the United States intends to prosecute the ongoing struggle against violence and terrorism ... and we are going to do so in a manner that is consistent with our values and our ideals." Was Bush watching on TV at home in Dallas cringing?

76 Signed second executive order requiring the closure of the CIA's network of secret overseas prisons, and making a commitment to not using torture in interrogations.

77 Signed third executive order establishing an interagency taskforce on detainees, including Hillary Clinton and the defence secretary, Robert Gates, to decide what to do with the remaining Guantánamo inmates.

78 Signed directive to delay proceedings in the case of Ali Saleh Kahlah al-Marri, currently awaiting a hearing at the supreme court, so that the president's team can review it. Marri is accused of being an al-Qaida sleeper agent.

79 Visited the state department, where Clinton had earlier made an introductory address to staff.

80 Watched, with impassive face, as Clinton said that she had appointed two special envoys to world trouble zones. The appointments had previously been billed as Obama's own. Was this a taste of rivalry to come?

81 Endured second gaffe by his vice-president in a week. Biden stepped into the tension between Obama and Clinton, saying at first that the president would announce the envoys and then hurriedly saying Clinton would present them.

82 Clinton got to name George Mitchell, the former Senate majority leader and Irish peace negotiator, as special envoy to the Middle East peace process. Obama later claimed him as his envoy. Who is in charge here?

83 Clinton named the former UN ambassador Richard Holbrooke as special representative to Afghanistan and Pakistan. Obama later names him as his envoy. Bully to you, secretary of state!

84 Called on Hamas to end its rocket fire into Israel, and for Israel to "complete the withdrawal of its forces from Gaza", adding that Gaza's borders should be opened to humanitarian aid.

85 Paid brief surprise visit to the White House press area, startling journalists. "Good to see you guys. I just wanted to make sure that I had a chance to say hello," he said. "I gotta say, it's smaller than I thought."

86 Observing that CNN and Rupert Murdoch's Fox News had adjacent booths, he likened them to the goal for Israel and the Palestinians: "Living side by side in peace and security," he noted.

87 Slight tetchiness entered the proceedings when a reporter asked a serious question about his nomination of a former lobbyist as number two at the Pentagon. "I can't come in and shake hands if I'm gonna get grilled every time," Obama said.

88 Said that he had won his fight to keep a Blackberry. The president will be given a $3,000 special version with encryption to secure his email exchanges with a very limited number of vetted correspondents.

89 Convened meeting with congressional leaders on the economic crisis.

90 Invited Republican leaders into the White House to air their discontent over the bail-out package. He is proving himself to be adept in defusing potential enemies.

91 Sat in on the daily briefing of the National Security Council giving updates on threats around the world.

92 Approves first American missile strikes under his presidency on tribal areas of Pakistan.

93 Started the first of what will now be a new daily series of briefings on the economy led by Larry Summers.

94 Budget meeting. With projections of an annual deficit of more than $1tr this year, there was plenty to talk about.

95 Rounded off a gruelling first three days with a meeting in the Oval Office with Timothy Geithner, his nominee for treasury secretary who is still embroiled in a drawn-out confirmation process in the Senate.

96 The Obamas had a choice of possible entertainments to round off their week. The choicest of all, most past presidents agree, is the private theatre, where they can watch Hollywood films before they are put on general release.

97 Back to the gym. There is no way Obama would miss his work-out on a Saturday.

98 Finally, a chance to take in the White House and its grounds at a slightly more relaxed tempo. The Obamas have said they will continue to spend weekends in their Chicago home, but this weekend is likely to be a time for acclimatising in their new residence.

99 Obama may take the opportunity to test out the White House basketball court. The court has been modified to put up two nets, allowing for a full game.

100 Obama retreats to his office on the first floor, puts his feet up on the desk, leans back and goes to light one of the cigarettes he has been struggling to give up. But alas smoking is banned in the White House.