Sydney touted its claim to be the New Year's Eve capital of the world with a spectacular display over the iconic Harbour Bridge using 7 tons of fireworks, its largest since 2000.
"Stunning, beautiful," said Cinthya Romo, 32, a Sydney-based interpreter from Chile who watched the 12-minute fireworks show from the Opera House.
"Sydney's best show yet," exclaimed George Stamp, who enjoyed the show with his children.
Luxury yachts and smaller boats filled the harbour to party on the water, while others crammed into pubs, clubs and only balconies with a view of the fireworks show.
At the Opera Bar Beach House, hundreds of people paid up to $500 for the view and a party with a beach theme.
"This has got to be the best place to be in the world tonight," said guest Marc Wilson, 41.
A few hours earlier, New Zealand and many South Pacific island nations were first to see in new year.
New Zealanders sang and danced their way into 2011, with firework displays and sold-out concerts entertaining revelers.
In the biggest city, Auckland, explosions of red, gold and white burst over the Sky Tower while tens of thousands shouted, danced and sang in the streets below.
In the southern city of Christchurch, thousands of partiers shrugged off a minor 3.3 earthquake that struck just before 10 p.m. and celebrated in Cathedral Square. The city has rumbled with thousands of aftershocks from a powerful 7.1-magnitude quake that damaged buildings across the city on Sept. 4.
As the clock ticked closer to 2011, cities across Asia readied for midnight events ranging from traditional prayers in Japan to a massive pyrotechnic display in the shape of a dragon in Taiwan. Europeans were looking forward to celebrations that could help them forget their economic worries.
In New York City, nearly a million revelers were expected to cram into the streets around Times Square to watch the traditional midnight ball drop. The 20-inch snowstorm that blanketed the city will be just a memory thanks to work crews and warmer temperatures.
At midnight Thursday - with just 24 hours to go - hundreds of people milled around Times Square as crews finished preparing TV sets for New Year's Eve broadcasts and vendors sold hats and noisemakers.
Among the tourists were students from Grand Valley State University near Grand Rapids, Michigan, who were scoping out a good location for Friday night and marveling at the preparations.
"For sure, we're going to be here," said Ahmed Lachheb, 23, from Sfax, Tunisia.
"I'm going to be here near the closest restroom just in case," added Mohamed Azuz, also 23, from Tripoli, Libya.
This year marks the first time Vietnam's capital, Hanoi, officially celebrates the new year with a countdown blowout, complete with a light show and foreign DJs in front of the city's elegant French colonial-style opera house.
Vietnamese typically save their biggest celebrations for Tet, the lunar new year that begins on Feb. 3. But in recent years, the Western influence has started seeping into Vietnamese culture among teens, who have no memory of war or poverty and are eager to find a new reason to party in the Communist country.
At midnight in Taipei, Taiwan, fireworks will form a spiraling dragon climbing up the city's tallest skyscraper.
In Japan, New Year's Eve is generally spent at home with family but those who venture out go to temples to pray for good luck in the new year. At Zojoji, a 600-year-old Buddhist temple in central Tokyo, thousands were expected to release balloons at midnight carrying notes with their hopes for 2011.
In the Philippines, powerful firecrackers have injured at least 245 people in recent days and Health Secretary Enrique Ona urged safety during Friday's celebrations, saying he feared up to 1,000 injuries.
Many Filipinos, influenced by Chinese tradition, believe that noisy New Year's celebrations drive away evil and misfortune. But they have carried that superstition to extremes, exploding huge firecrackers sometimes bigger than dynamite sticks to welcome the new year.
In Europe, many people will be partying simply to forget their economic woes after a year that saw Greece and Ireland needing financial bailouts and others, such as Spain and Portugal, battling speculation that they will need similar aid.
In London, thousands will witness a musical and firework display at the 135-meter high London Eye, located on the southern banks of the Thames River. The Eye, which is celebrating its 10th anniversary, lies almost opposite the Big Ben clock tower at Parliament that will chime in 2011.
If not at home or at private parties, Spaniards traditionally gather in their main town squares to eat 12 grapes one by one as the bell in the square marks the countdown to 2011.
In Berlin, German Chancellor Angela Merkel said in her New Year message that Europe is dealing with a major test and must strengthen the euro, even as she celebrated Germany's emergence from the economic crisis, powered by strong exports.
Merkel said in her televised message being broadcast Friday that "it was a good year for Germany."
Associated Press writers around the world contributed to this report.