There is worldwide optimism that Barack Obama's presidency will improve US relations with the rest of the world, a BBC World Service poll suggests.
In the poll of more than 17,000 people in 17 countries, about 67% said Mr Obama would strengthen US relations abroad.
Many are hopeful that Mr Obama will make the global economic crisis his top priority and will also focus on pulling US troops out of Iraq, tackling climate change and brokering Middle East peace.
Here BBC News website readers from around the world share their views on Obama's inauguration.
DAVID ALUSA, 25, STUDENT, KAKAMEGA, KENYA
The speech was fantastic, it was full of optimism. Even here in Kenya we feel inspired - we feel we can achieve so much.
Everybody is very proud that there is a man in the White Hose with Kenyan heritage.
We are looking for change. And we think Obama will be able to make a difference in Africa.
I watched the event on a big screen with many other students. There was a fantastic atmosphere, people were excited, clapping throughout, acting as though they were there in Washington.
We are looking for change. And we think Obama will be able to make a difference in Africa. You never forget where you come from.
I just want to say to all the readers that everyone should follow the example of Obama.
RANA EL-MENSHAWI, 24, JOURNALIST, CAIRO, EGYPT
I like Obama because he really represents the awaited change in the US. But as an Egyptian, I don't think it'll have a major effect on my life, country or nation. I guess things will stay the same.
I've noticed a few shops playing the speech on my way home. But to be honest, the Egyptian people couldn't care less about this. They would have cared more if it was a football match or a famous TV soap!
Only the people in the media, half-Americans, politicians, political science students or politics fans watched the inauguration. Even upper, educated, middle-class families didn't bother.
Arabs at large, and Muslims specifically, have never witnessed a change in American foreign policy relating to their nations for decades, so why should they care now?
Obama's speech was predictable. It was expected that he wouldn't go into details about Muslims. It was a speech for the United States, which is fair enough.
I think Arabs should cease relying on American presidents to change their lives and end the phobia against them.
Obama isn't "The Change" for the world. He might be to the US but sadly not to our region.
HALUK DAG, 28, JOURNALIST, ISTANBUL, TURKEY
Like everywhere around the world, people in Turkey were very interested in Obama's speech. It was the headline news on every TV channel.
I watched Obama's speech at home. I think he made a historic and emotional speech. I think a new and better era has already begun for the US and the rest of the world.
Unlike George W Bush, the new president talked about peace; that's the difference. During Bush's era, the Muslim world was seen as an enemy. We often heard the terms "axis of evil" and "crusade", among others.
Now Obama is extending an olive branch to the Muslim world. I think it will be appreciated that he addressed the Muslim world specifically in his speech.
I think it will be appreciated that he addressed the Muslim world specifically in his speech.
I'm very hopeful about Obama's term but the new president is facing a deep economic crisis, endless wars in Iraq and Afghanistan and, to be honest, hatred for the image of the US.
It may take a while for him to help improve America's reputation around the world.
George W Bush completely destroyed the strong American economy that was booming during Bill Clinton's administration.
Now, everybody is suffering in this economic crisis. During his speech, Obama gave some indications about his policies. Dealing with the economic problems will be a burden for him but I feel certain that he will succeed.
I'm pretty sure that in a short time Obama will regain the hearts of the Turkish people. Young people seem especially drawn to him, just as they do in the US and around the world.
PANCHA CHANDRA, 58, JOURNALIST, BRUSSELS, BELGIUM
I watched at home with some friends. I thought Obama was actually a little nervous when he delivered his speech - and that only showed him to be more human. It added to the poignancy of the moment.
You could see the emotion written into his face. You could see that he was speaking from the heart.
I thought he did make an attempt to reach out to the world. He showed that he is going to be a very different type of leader from his predecessors.
Many people here in Belgium were interested in what he had to say. After all, what happens in America affects the whole world.
America is certainly on the ascendency thanks to this dedicated charismatic man. Obama offers real hope in this time of economic distress.
CALEB ESSAJEE, 59, SPECIALIST NURSE, BERGEN, NORWAY, ORIGINALLY FROM KENYA
I wish I could have been at the inauguration but at least I was able to follow it on the BBC. I watched it at home with my wife and children.
This is history and everybody would have liked to experience the moment.
I'm from Kenya originally and very proud that Mr Obama made it to the White House. Many Kenyans see him as a blood brother.
And here in Norway too I bet many people stayed at home to catch the moment on TV.
Watching the speech, I am sure the right choice was made.
It is high time that America reached out a hand to other countries. I liked what Obama had to say about doing just that. It is time that we lived in peace and love and hope.
I think Obama will be the president not just of America but of the whole world
I think Obama will be the president, not just of America, but of the whole world - because he has the vision to understand how the world has changed.
Let us see how as a leader of America and the world he can overcome past and present mistakes.
KERRY BERGER, 50, MARKETING DIRECTOR, BANGKOK, THAILAND
I'm an American citizen originally from Hawaii. I watched the speech late into the night with my wife.
It was a sharp speech and I was surprised how it was notably less optimistic than his previous statements. Obama seemed to be saying now is the time to get down to the hard work.
I was also surprised by his sharp criticism of previous administrations.
I am excited about witnessing the transition of power - hopefully we'll now see a 180-degree shift in policy.
I am elated and pleasantly optimistic about the future. There are many hurdles to overcome and a lot of hard work to do to succeed but yes we can, and yes I can, and we shall do it as Americans.
This is the mood I feel even from afar in Bangkok, Thailand. It is the spirit of cooperation I would like to help foster.
The mood among Thais is also very positive - though many in my office doubted he would make it this far. People now hope that America is going to start to act differently - that America will no longer bully smaller countries.
I have no illusions that one man can solve everything. But collectively we can move mountains.
SONJA SABITA TEELUCKSINGH, 33, RESEARCHER, VENICE, ITALY, ORIGINALLY FROM TRINIDAD
The inauguration is of immense and special significance, not just to America but to everyone of a minority race across the world.
I myself am of minority race - my ancestors moved from India to the Caribbean several generations ago.
I watched the event online. Italian people seemed less interested than my friends back home. Many friends back home said they would be glued to their TV sets.
It was a brilliant speech. As an international viewer, I was pleased about his references to a common humanity in a shrinking world.
I also like the fact that he referenced his father from a small African village. This surprised me as I know he has tried to play down his racial background. He doesn't want to be defined by his race alone.
No matter how his presidency unfolds, Obama - and the people who voted him into power - have already changed the world for the better. This is a moment of great hope for humanity and for the future. Words cannot express.
Many say don't be too optimistic - wait and see what will happen. But I think they underestimate the true significance of this day which represents a real shift in the world order.
GERALD MULONGOSHA, 43, TEACHER, NKONI, UGANDA
I watched the speech with 300 students and staff at St Joseph's Secondary School, where I teach geography and computer studies. We had two US Peace Corps volunteer amongst us.
The atmosphere was very expectant.
In an earlier mass, the priest prayed for Obama's success, and during the anthem all students stood up, which was followed by cheering and clapping.
There was dead silence during the 44th president's speech.
Obama has the capacity to transform the world vision and leadership in Africa, as on his speech he talked about issues like corruption.
I think the future is very bright, but the new president should act with a lot of caution as many out there can work for his downfall.
MARYAM SOOFI, 32, MEDIA, LAHORE, PAKISTAN
I watched the inauguration speech at home on the BBC. The clear message to Americans, conveyed very beautifully by the president, was to wake up and rise to the challenges the US faces right now.
The people of Pakistan are relieved that Bush has gone and a new era has started. We are nervous but optimistic.
Pakistanis are interested and not hopeless as they were during Bush's time in office. People were very happy about the message of peace which president Obama mentioned while addressing the Muslim world.
I feel overwhelmed with the change America is going through. The world has never seen Americans so united before under one great cause of rebuilding America.
Just seeing the number of people attending the inauguration demonstrated how Americans wanted a change from the Bush era.
The future holds challenges for the entire world at the moment in history but those challenges can be met with the strong values of humanity. Obama can definitely make a difference for America and Pakistan and the world.