Barack Obama was elected on a message of change. Now he is in office, change is expected both in foreign and domestic policy. Here the BBC's team in Washington tracks developments in the first 100 days of the Obama presidency.
TUESDAY 10 MARCH - DAY 50
2200 EST Cuba policy review
Sarah Morris: It must be one of the longest trade embargoes in history. For more than half a century the US has held the Castro regime in Cuba at arm's length.
But now there are signs - very small ones - of a loosening up.
The Senate has just voted to approve two clauses of the Spending Bill, one which will allow Cuban-Americans to travel to their homeland every year instead of once every three years and another which will make it possible for a small, select group of US businesses to go to the island to market and sell agricultural and medical equipment.
President Obama and other administration members feel that after 50 years, and Fidel Castro's retirement, it's time to review US policy towards the Cuban government.
However, we're unlikely to see planeloads of US holidaymakers bound for sandy Cuban beaches and the urban delights of Havana anytime soon. Mr Obama has made it clear that the trade embargo should stay firmly in place without evidence of democratic reforms.
As for the new bits of legislation on the books tonight - they didn't go through without a fight.
Senators from states with large populations of anti-communist Cuban-Americans were less than happy. Two of them - New Jersey's Robert Menendez and Florida's Bill Nelson, both Democrats, only agreed to vote in favour (and thus ensure the legislation got passed) after receiving reassuring letters from Treasury Secretary Timothy Geithner.
1700 EST Backpedalling on China?
Kim Ghattas: China's foreign minister, Yang Jiechi, arrives in DC today and will hold talks on Wednesday with Hillary Clinton, and Treasury Secretary Timothy Geithner.
There will be lots to talk about, from the continuing economic crisis to climate change as well as rising tensions after the incident at sea. It's also likely that Tibet will come up.
It's not clear what Clinton will tell Yang or how tough she'll sound. The Dalai Lama certainly sounded fierce today when he said his people had been "put through hell". He was speaking on the 50th anniversary of the Tibetan uprising.
During her Asia trip, Hillary Clinton said that while human rights would remain on the agenda in talks with the Chinese, it should not interfere with attempts to cooperate with them on other issues, like climate change and the economy. This has led to criticism and accusations of backpedalling on human rights in her talks with the Chinese, but also with the Egyptians, Turks and others.
A State department spokesperson said the criticism was unfair because Mrs Clinton had devoted a lot of her career to human rights and would continue to do so, but she also understood the limitations of what could be achieved by raising the issue during official meetings, so she had tasked her staff to come up with new, creative ways to influence the situation.
It's slightly unfortunate though that the Chinese foreign minister arrives in DC precisely on the day of anniversary of the Tibetan uprising...
1520 EST Battle is joined
Max Deveson: The introduction of the Employee Free Choice Act (EFCA) is the first shot in what could prove to be one of this year's most bruising congressional fights.
EFCA is the American trade union movement's biggest legislative priority, but it is vehemently opposed by big business.
The act would make it easier for unions to organise - workers would indicate their preference for a union to be recognised by their employers by signing an authorisation card (the measure is also known as "card check").
Employers say EFCA would do away with the secret ballot, and could lead to union coercion. The unions say the deck is already stacked in the employers' favour, and that under the terms of the act workers would be free to hold secret ballots if a third of workers in the firm demand it.
President Obama supports the measure, and the House of Representatives is also likely to pass the bill.
But the real battle will be in the Senate; if moderates from both parties baulk at it, the bill will not pass. If recent comments from Arkansas Democrat Blanche Lincoln - "the bill is divisive and we don't need that right now" - are any indication of moderates' thinking, the bill is going to encounter some difficulties.
1200 EST Halfway there
Kevin Connolly: As President Obama reaches the half-way point of his first 100 days, I took a look at the eventful first 50 days.
MONDAY 9 MARCH - DAY 49
1804 EST Another Bush policy reversed
Jonathan Beale: As expected, President Obama has announced his decision to overturn his predecessor's ban on federal funding for new stem cell research.
As I point out in this article, the ruling is one of a growing number of changes that the new president has made to George W Bush's policy legacy.
SUNDAY 8 MARCH - DAY 48
1830 EST Back from her travels
Kim Ghattas: The overall theme of Hillary Clinton's second trip abroad was further outreach and more public diplomacy.
In the Middle East, she attracted smaller crowds overall than during her Asia trip but she was still immensely popular and often got effusive applause.
The outreach was meant for both foes and allies. She tried to rekindle strained ties with Europe and Turkey, she worked to thaw relations with Russia but crucially, in a clear break with the Bush administration, she reached out, in public to Iran and Syria.
She invited Tehran to attend a conference on Afghanistan later this month. The Iranians have said they will attend.
And she sent two senior envoys to Damascus, which has had icy ties with Washington for almost five years.
Will engagement yield results? It's still too early to tell. But Hillary Clinton's strategy is this, in her own words: "Something positive might actually happen. You never know. But if you stand at opposite sides of the room and refuse to engage, it's guaranteed nothing will happen."
FRIDAY 6 MARCH - DAY 46
1734 EST Stem cell ruling
Max Deveson: President Obama is to lift the ban on federal funding for research on new stem cell lines, according to reports.
The move is a campaign pledge, but will be no less controversial for that.
1306 EST Empty Treasury?
Kevin Connolly: Treasury Secretary Timothy Geithner seems to be finding it harder to swear in deputies than Gary Cooper on the eve of his gun battle with the bad guys in "High Noon".
Senators conducting a hearing into the AIG insurance group asked for a representative from the Treasury to appear and were told no-one was available.
And two of Mr Geithner's nominations for senior positions - Annette Nazareth and Caroline Atkinson - are said to have withdrawn from the process, although there's no suggestion that either of them has failed to pay their taxes or is in any other way disqualified from government service.
Ms Nazareth once worked at the Securities and Exchange Commission and may have been worried that some might have held her partly responsible for the lax financial oversight which helped set the stage for the current crisis.
But isn't it possible that having had its fingers burned with so many appointments in one way or another the administration is responding by making the vetting process so onerous that high-flyers are put off the idea of government service?
THURSDAY 5 MARCH - DAY 45
1730 EST The road to Iran runs through Russia
Kim Ghattas: At the Nato meeting in Brussels today, Washington and its partners announced the resumption of high-level ties with Moscow.
Secretary of State Hillary Clinton spoke of a great potential for co-operation with Russia on a range of issues, including Afghanistan and Iran. The US is hoping Moscow will help secure new and safer supply lines for Nato troops in Afghanistan.
But the thaw is also part of a carefully orchestrated and very cautious dance by Washington to engage Iran and curb its nuclear plans. Russia's help will be crucial.
Mrs Clinton called for an international meeting on Afghanistan later this month, under UN auspices, and said Iran would be invited. It is the first public overture to Tehran by the Obama administration.
Iran has not yet responded, so we do not yet know whether President Barack Obama will find that "unclenched fist" that he is hoping for, but his administration and his Secretary of State are keeping a realistic, pragmatic attitude.
Mrs Clinton will meet her Russian counterpart, Sergei Lavrov, in Geneva on Friday. Iran will be high on the agenda and the Secretary of State will be hoping that today's developments in Brussels will pave the way for a positive meeting.
1719 EST Healthy democracy?
Max Deveson: President Obama presided over a healthcare summit today, where he reiterated that he was not wedded to any specific plan for health reform - he just wanted "to figure out what works".
Present at the meeting were dozens of congressmen, as well as representatives of doctors, patients, insurance companies and pharmaceutical firms.
The event is part of Mr Obama's strategy to get a healthcare reform bill through Congress by the end of the year.
It's at meetings like this where the details of the reform package will be hammered out - Mr Obama hopes to get all of the stakeholders on board to ease the passage of the legislation.
1158 EST Grey matter
Rajini Vaidyanathan: Is all the stress of being president going to Barack Obama's head, quite literally?
Several news websites have noted that the president's hair has been getting as white as his house.
During the campaign, a theory was doing the rounds that President Obama had been grey for sometime, but at the start of the campaign had started dying his hair. His barber dismissed the suggestion, however.
Whatever the truth of the matter, these days Mr Obama seems quite content to acknowledge his changing hair colour
A few months ago he told a campaign rally that the "the grey is coming quick," and "by the time I'm sworn in, I will look the part."
Perhaps those who are splitting hairs (excuse the pun), about the president's more distinguished look should relax. If he's happy, then what's the big deal?
The burdens of office? - Barack Obama (left) on 12 February 2009 and (right) on 19 September 2008.
WEDNESDAY 4 MARCH - DAY 44
1709 EST What America has been focusing on
Max Deveson: Although Gordon Brown's US visit has been the main focus of the British media today, America's attention been directed more towards President Obama's call to cut the amount of money government spends on outside contractors.
Mr Obama has also been challenged to a debate by conservative talk radio host Rush Limbaugh.
Mr Limbaugh's star has been in the ascendant of late, as I noted in a piece on the current state of the Republican Party.
TUESDAY 3 MARCH - DAY 43
1700 EST Good and bad news
Kevin Connolly: Yesterday we learned that the US savings rate hit 5% in January (which means that Americans banked five dollars out of every hundred dollars that they earned).
In January last year, the rate was 0.1% and even that was an improvement on 2005 when America as a whole actually spent MORE than it earned.
So far so good. In the long run, a solid savings rate is a good thing. But sometimes you have to read one set of statistics in conjunction with another.
Consider this, for example. In January, General Motors' sales fell by an eye-watering 53% and neither Ford nor Toyota fared much better.
So saving, a good thing in the long run, can be destructive in the short-term because no spending means no sales and no sales means, in the end, no jobs.
Have Mr Obama's attempts to convey the severity of the recession panicked Americans into cutting back so hard that their thriftiness is hurting the economy?
1200 EST Russian overtures
Adam Brookes: Officials at the White House say that President Obama has sent a letter to President Medvedev of Russia suggesting the US may be prepared to scale back plans for a missile defence system in Europe if Russia collaborates on Iran policy. We don't know exactly what was in President Obama's letter to his Russian counterpart, but it was delivered by hand a few weeks ago and officials at the White House say it covered all sorts of issues of contention between Washington and Moscow. Among them was the American plan to deploy missile defences in eastern Europe, something the Russians are very unhappy about.
The letter suggested that America might be prepared to put those plans on hold and in return the Russians would be asked for greater cooperation on Iran and on international efforts to limit the Iranian missile and nuclear programmes.
It's a trade-off that has been talked about for a while in Washington. Missile defence is an expensive and so far relatively unreliable weapons programme and jettisoning it might allow the Obama administration to take some of the stress out of US relations with Russia, while getting valuable help on Iran in return.
1145 EST US envoys to Syria
Kim Ghattas: Hillary Clinton has announced that two US envoys will travel to Damascus for talks - this is the Obama administration's clearest and biggest break on Middle East policy with the Bush administration so far.
Relations between the US and Syria have been icy for about five years and there's been no ambassador in Damascus since 2005.
Senior US officials tell me that Jeffrey Feltman and Dan Shapiro will be in Damascus on Saturday - they handle the Middle East at State and at the National Security Council. The talks were described by Clinton as preliminary.
This is probably not going to be a cakewalk for the Syrians. Feltman was ambassador to Lebanon during the "Cedar Revolution" when thousands of Lebanese demanded a Syrian troop withdrawal in the aftermath of the assassination of former Prime Minister Rafik Hariri. Syria claimed the pro-Western camp in Lebanon was being manipulated by Feltman.
Shapiro formerly worked for Senator Bill Nelson and helped draft the Syria Accountability Act of 2003, which slapped further sanctions on Damascus.
MONDAY 2 MARCH - DAY 42
1330 EST Sebelius at Health
Max Deveson: The speculation turned out to be correct. Kansas Governor Kathleen Sebelius will be Obama's nominee for Health and Human Services Secretary, replacing the tax-challenged Tom Daschle.
But Ms Sebelius will have less control over the passage of healthcare reform than Mr Daschle would have done.
Had he not withdrawn his name, he would have served as both health secretary and head of the White House Office for Health Reform, but with Mr Daschle out of the picture, President Obama is sharing the roles between two people - Ms Sebelius will run the department, while Nancy-Ann DeParle will take up the White House post, with responsibility for pushing reform legislation through Congress.
Bill Clinton's healthcare reform efforts suffered because too many people were running the show - will Obama's plan endure a similar fate?
1252 EST 'The wrong hands'
Kim Ghattas: Hillary Clinton today sent a clear signal that the US position on Hamas remained as tough as it was under Bush and for years before that.
At the Gaza aid donor conference in Egypt, she said: "We have worked with the Palestinian Authority to install safeguards that will ensure that our funding... does not end up in the wrong hands" - ie Hamas.
The US and the other donors, including Arab states, are keen that the $4.5bn pledged props up the Palestinian Authority and does not end up helping Hamas rebuild its infrastructure or its popular support base in Gaza.
The move has drawn some interesting reactions. Hamas, which was not invited to the conference, said that despite Obama's promise for change: "Clinton is using the same language of the former Bush and Rice (administration), and... her recent statements about the conditions for reconstruction are... not logical."
Asked whether he saw a major shift from the Bush administration's Middle Eastern policy, Egypt's Foreign Minister Ahmad Abulgheith said: "No, I don't think so."