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.
THURSDAY 9 APRIL - DAY 80
1712 EDT "Black sites" to be closed
: President Barack Obama has moved quickly to draw a line under the techniques used by the Bush administration in what it styled the War on Terror. The closure of the Guantanamo Detention centre was announced, the use of torture by US agencies was prohibited and the phrase "war on terror" itself abandoned.
Now CIA Director Leon Panetta has said the so-called "black sites" - where suspects were subjected to techniques such as waterboarding - have been closed and are to be decommissioned
The statement has an impressive ring, but the CIA's secret prisons - probably in Eastern Europe - may never have been elaborate affairs in themselves and decommissioning may be straightforward.
The key issue for the Obama administration will be its policy towards enemy fighters who fall into its hands, not the buildings in which they're held.
Mr Panetta makes it clear the CIA retains the authority to detain individuals for short periods before handing them on to the US military or to their own governments, but he said future American interrogations would be "debriefings" carried out in what he called a "dialogue" style.
WEDNESDAY 8 APRIL - DAY 79
1614 EDT Talking to Iran
: Washington has announced that it will start participating in group talks with Iran about its nuclear programme. It's a clear departure from the policies of the Bush administration which had shunned talks. (A US official did participate in the discussions last year, but only once.)
The negotiating group - known as the P5+1 - brings together Russia, China, France, Germany, the UK and the US, meets regularly and they will now invite Tehran to attend the next meeting.
The Obama administration's policy shift on Iran may not have been the subject of a formal announcement, as happened with the Afghanistan and Pakistan strategy review, but it is already being implemented.
After the president's video message to the Iranian people and their leaders last month, Secretary of State Hillary Clinton has now said that the US would become a full participant in the group talks with Iran over its nuclear programme - a clear departure from past US policies in two ways.
Firstly, the mere attendance of American officials can create a new dynamic. And secondly, the nature of America's participation will change. When Undersecretary of State William Burns attended one meeting last year, his participation in the talks was very restricted - the restrictions will now be lifted .
The American decision has been warmly welcomed by the P5+1. Western diplomats expect that further steps taken by Washington could include a lifting of the ban on contacts between senior American and Iranian diplomats around the world.
TUESDAY 7 APRIL - DAY 78
1437 EDT Michelle in wax
: If their whirlwind world tour is anything to go by, Michelle Obama is becoming as big an attraction as her husband.
Little surprise, then, that a new waxwork of the First Lady has gone on display in Washington DC.
The likeness is actually quite good - her penchant for sleeveless dresses, which have become the subject of much debate is evident even in wax, with the model First Lady sporting a red number which shows off her bare arms.
The waxwork is on display at Madame Tussauds in Washington and will sit alongside a model of President Obama which is already on display.
Can we expect First Daughters Sasha and Malia to be immortalised in wax too? And what about that First Dog¿?
1234 EDT Obama's surprise Iraq visit
: Presidential trips to war zones are always "surprise visits", because - for security reasons - we are never told about them in advance. But
as Justin Webb points out
, most people travelling with President Obama expected him to travel to Iraq or Afghanistan while he was in the region.
Mr Obama told US troops serving in Iraq that it was time for Iraqis to "take responsibility for their country", which drew cheers from the soldiers.
He will now fly back to the US, where he will turn his attention to more pressing matters - passing his budget and choosing a puppy.
MONDAY 6 APRIL - DAY 77
1609 EDT Battles ahead over defence budget
Some of the US military's most high-profile weapons programmes may be falling victim to the unrelenting axe of Robert Gates.
The Secretary of Defence says he wants to save money. He wants the military to stop buying weapons that were designed with the Cold War in mind. And he says he wants to impose the lessons of the low-tech wars in Iraq and Afghanistan.
The F-22 - an advanced and hugely expensive fighter aircraft - will end production. F-22s cost $150m each, but they're not used in Iraq or Afghanistan. A new helicopter especially for the President (cost: $11bn) has been canned. And big changes are being made to the missile defence programmes, to shipbuilding for the Navy and much more.
However, overall, the US defence budget will still rise this year. The US accounts for about 40% of all military spending in the world.
Mr Gates's plans must still go to Congress for approval. There we can expect a battle. Members of Congress guard closely the jobs and income which come to their districts from military spending. And they won't give them up without a fight.
So for President Obama and Secretary Gates, there are political battles ahead before we'll see these ambitious plans realised.
1350 EDT Obama's Turkish speech
BBC North America Editor Justin Webb
: This - for the Turkish government and for many Turkish people - was quite a day.
There were some anti-American protestors and around 20 were charged by riot police outside the Turkish parliament, but generally there was a warm welcome.
Foreign visitors down the years have paid homage at the tomb of Turkey's founder, Kamal Ataturk, but for Barack Obama to make this such an early stop on his first visit overseas is being seen here as a sign of something new, which is exactly what the president intends. He was here to build bridges.
George W Bush supported Turkey's right to join the European Union, but Barack Obama went further today, admonishing those Europeans who were hostile to the idea.
And in a wider message intended to be heard across the Middle East, Mr Obama said America was "not at war with Islam".
There are some back in the United States who wonder whether Mr Obama is going too far, but his intention seems clear. He is on a mission to charm with the hope that in years to come there is a tangible benefit for America and the world.
1252 EDT Media get access to return of dead US soldier
: With the chilly silence broken only by the briefest military words of command, the American military authorities brought the flag-draped coffin of Staff Sgt Philip Myers home to his family.
He died in Afghanistan at the weekend - killed by an improvised explosive device - and became the first American serviceman publicly welcomed home in this short, grim ceremony for 18 years. The American government banned public coverage of such ceremonies during the Gulf War in 1991.
Critics of the ban on media coverage of such events always felt it was an attempt by the American government to disguise the human cost of war from public opinion - Barack Obama ordered a review of the policy shortly after he took office.
Some historians believe that widespread media coverage of the repatriation of dead American service personnel from Vietnam helped to turn the public mood against that conflict in the late 1960s and early 1970s.
It remains to be seen how prominently such ceremonies will be featured by the American media as US operations in Afghanistan and Iraq continue - and what effect they will have on attitudes towards the fighting.
FRIDAY 3 APRIL - DAY 74
1051 EDT The Obama tour continues
The BBC's North America Editor Justin Webb is still following President Obama on his tour of Europe. Read his thoughts on
the way the President's press team is handling the trip
the way the President is handling the press
Justin Webb adds
: President Obama has appealed not only for more help in Afghanistan but also for better transatlantic relations. So far he has received a warm welcome from this hosts at the NATO summit. He was also given an ecstatic reception when he visited a sports arena to take questions from students.
1004 EDT Budget resolutions pass
: Both houses of Congress have approved budget resolutions for 2010 in line with President Obama's spending plans.
The House voted through a $3.6tn budget with 233 votes for and 196 votes against. The White House welcomed the House vote saying that it was another step to rebuilding America's struggling economy. In a statement President Obama said the House budget embraced his fundemental priorities for green energy, improved education and health care.
The House's budget resolution differs slightly from the plan proposed by the President last month. But the vote is still a victory for Barack Obama, who says the increase in spending is essential for America's economic recovery.
Republicans have been bitterly opposed. They've called the Democrats' budget a road map to disaster. But the Republican's rival plan to slash spending and to cut taxes was voted down, with 37 moderate Republicans joining the Democrats in opposition.
The Senate voted 55-43 for its resolution, which differed slightly from the House version. Differences between both versions will have to be worked out before a final budget is approved.
THURSDAY 2 APRIL - DAY 73
1730 EDT How is Obama being viewed back in the US?
: The president is getting some pretty good write-ups on this side of the Atlantic.
Jonathan Martin, at Politico
, suggests the G20 should perhaps have been renamed "the O20".
"Barack Obama commanded centre-stage at this high-wattage gathering of the world's industrialized nations," he writes, "vacuuming up attention both inside the summit and throughout a sophisticated city not easily star-struck."
Matthew Yglesias from liberal think tank the Centre for American Progress
notes the difference that having a popular president makes:
"We... saw the difference between a situation in which, at the margin, world leaders would prefer to be seen as cooperating with the President of the United States and the situation that previously prevailed in which, at the margin, world leaders would prefer to be seen as hostile to the President of the United States."
The New York Times's Paul Krugman
disputes Mr Obama's description of the summit as "a turning point", but admits that while "realistically, most big-time international meetings produce nothing; this did something significant."
But the conservative commentator, Mark Steyn, writing at the National Review
, was quick to mock the media's uncritical appraisal of the trip. Quoting a reader, he says that talk show host Rush Limbaugh "should cease calling them the "drive-by media": After their coverage of the Obamas in London, they're more like the drool-bys."
WEDNESDAY 1 APRIL - DAY 72
1519 EDT The Obamas in London
The BBC's North America Editor Justin Webb is following Barack Obama as he travels round Europe.
Here's his first take
on the London leg of the trip.
TUESDAY 31 MARCH - DAY 71
1745 EDT Cuba (travel) libre?
: When something hasn't worked for 50 years, it's time to try something different.
This was the very straightforward explanation lawmakers gave on Capitol Hill today when they explained why they were introducing the Freedom to Travel to Cuba Act, which would lift restrictions on Americans travelling to Cuba.
Calls have been growing here for a change in Washington's policy towards the communist island. Earlier this month, Congress voted to ease restrictions imposed in 2004 by President George W Bush on travel and remittances for Cuban-Americans.
The new bill would allow unrestricted travel for everybody from the US to Cuba. But no one is yet calling to lift the trade embargo. Lawmakers supporting the bill said US policy provided the Cuban government with an excuse for its problems and a justification for its policies - the best agent for change would be visitors from the US.
The same bill was proposed two years ago but died quickly. Policy change on Cuba has faced stiff resistance from the influential Cuban-American community in Florida. This time, the bill seems to have enough backing to be adopted, but it will likely provoke a lively debate.
1408 EDT Obama's European tour
Barack Obama has embarked on his tour of Europe.
The president will spend a few days in London, where he will attend the G20 summit, before heading to Strasbourg for a Nato summit and Prague for an EU-US summit. He will then fly to Turkey - his first visit to a Muslim country as president.
The London leg of the tour will be focused on economic policy - Gordon Brown wants world leaders to sign up to a new system of global financial regulation. The rest of the trip, Mr Obama will change his focus to issues of war and peace - the continuing military operation in Afghanistan, and a new direction on nuclear non-proliferation.
Above all, perhaps, it will be a chance for Europeans to show the new president some love - he is incredibly popular there, and any public appearance he makes is likely to be a melee of adulation.
He'll probably need some pretty heavy security...