CBS News correspondent Sheila MacVicar reports the senator's pending whirlwind tour of Europe and the Middle East is a chance for Americans to see how he measures up as a statesman, and a chance for citizens of foreign countries to take a closer look at a man who will make a big impact on their lives if he becomes president.
A 12,000-mile trip in the middle of an election campaign is an unusual choice for any candidate, but for Obama it's an attempt to demonstrate he has the necessary gravitas to maneuver through diplomatic minefields - especially in the volatile Mideast.
He'll head to Iraq, where people are well aware of his proposal to withdraw all U.S. combat troops within 16 months, should he win America's top job.
American presidents have been unpopular in Iraq for almost 20 years, but many Iraqis say they do support the notion of seeing U.S. troops go home.
"I'm for withdrawal now," one Baghdad shopper says. "The Americans have caused all our problems." If Obama's plan is genuine, the shopper says, "we bless it, we need withdrawal today."
Meanwhile, Obama has already angered Palestinians by saying that "Jerusalem will remain the capital of Israel and it must remain undivided."
President Clinton proposed Jerusalem as the capital of both Israel and Palestine.
Obama has had to backtrack, but Palestinians and Israelis have been left wondering if he really understands the complexity of their situation.
Then, on to Europe, where many are enthusiastic about the young senator's campaign.
However, Germany's chancellor has accused him of over-reaching his status. The Obama campaign's request to speak at the Brandenburg Gate - made an icon of freedom by President Reagan's famous "tear down this wall" speech addressing then Russian leader Mikhail Gorbachev, has been rejected.
That location, the German government says, is reserved for elected presidents.
There's no question that Obama, more than any other recent presidential candidate, excites great interest, even this far away, says MacVicar, but his meetings with presidents and prime ministers will be a little more formal as there is no point in building a very warm relationship if he doesn't end up the inhabitant of the White House next January.
"I don't know the time a challenger has had the focus that Barack Obama has. This is more attention to a foreign trip than even President Bush would get," said political analyst and pollster Frank Luntz of the buzz being generated by Obama's trip.
"They're going to line up by the thousands to get a chance to wave at him. He will get a good response in every country, except Israel," Luntz told CBS' The Early Show.
But Obama has no chance to let his guard down and bask in the glory during this trip, cautions Luntz. "One slip up, one mistake, and John McCain will pounce.
"He's only been a senator for three years," says Luntz. "So, a lot is at stake here."