(AP)- New Year's revelers welcomed 2008 with parties, fireworks and hopes for peace and prosperity.
But reminders of violence were apparent as security was tightened in many nations.
Fireworks were canceled in downtown Brussels, Belgium, where police detained 14 people Dec. 21 suspected of plotting to help an accused al- Qaida militant break out of jail.
Festivities in Paris centered on the famous Champs- Elysees avenue and the Eiffel Tower, where about 4,500 police and 140 rescue officials patrolled the streets.
In Thailand, an army spokesman said he believed that five bombs set off by suspected Muslim insurgents in a Thai-Malaysian border tourist town likely targeted New Year's revelers. The bombs, which wounded 27 people, exploded in the hotel and nightlife quarter of Sungai Kolok , spokesman Col. Akara Thiprote said.
Baghdad witnessed something Iraq had not seen since before the invasion of 2003 - people publicly partying to welcome in a new year.
The ballrooms of two landmark hotels - the Palestine and the Sheraton - were full of people for New Year's Eve celebrations. After years of car bombings, mortar fire and suicide attacks, Iraq's capital was sufficiently calm to warrant the two high-end parties in the once-posh hotels.
Several European countries rang in the new year with new habits.
The smoke-filled cafe became a thing of memory in France. Following up on a ban last year on smoking in many indoor locations, cigarettes were prohibited in dance clubs, restaurants, hotels, casinos and cafes.
Fabienne Simon, a 27-year-old smoker, said the ban was "not that bad."
"There is nothing better than to go to a nightclub, a coffee place where there are no cigarettes," she said. "You come out, it's great, you aren't smelling of cigarettes."
Two European Union newcomers, Cyprus and Malta, started using the euro at the stroke of midnight. The Mediterranean islands, both former British colonies, were scrapping the Cyprus pound and Maltese lira to bring the number of countries using the shared currency to 15.
In France, President Nicolas Sarkozy gave the first traditional New Year's greeting of his presidency, with a "message of hope, faith in life and in the future." In Russia, Vladimir Putin delivered the last New Year's Eve address of his eight-year presidency, boasting of economic improvements and claiming to have restored a sense of unity among Russians, who are likely to see him stay in power as prime minister after he steps down in a few months.
In Moscow, thousands gathered in Red Square, watching a concert beneath the colorful onion domes of St. Basil's Cathedral, and fireworks above.
An ailing Fidel Castro saluted the Cuban people for their "50 years of resistance" against the United States in a message that was read on state television. Though Cuba will mark the 50th anniversary of the Jan. 1, 1959, revolution that brought Castro to power a year from now, it is characterizing all of 2008 leading up to that date as the "50th year of the revolution."
Along with the innovations, old traditions were maintained.
More than a million revelers in New York's Times Square cheered at the 100th drop of a giant ball. A century ago the tradition began with a 700-pound ball of wood and iron, lit with 100 25-watt incandescent bulbs. This year's event featured an energy-efficient sphere clad in Waterford crystals, with 9,576 light-emitting diodes that generated a kaleidoscope of colors.
In London, people gathered in Trafalgar Square and along the banks of the River Thames to watch a fireworks display and hear Big Ben - Parliament's iconic bell - welcome the New Year with 12 resounding bongs.
Berlin held a massive fete: In a stretch leading from the city's famous Brandenburg Gate along Tiergarten park to the western part of town, officials set up three stages, 13 bands, a 40-yard tall Ferris wheel and over 100 beer stands and snack joints.
In Vatican City, Pope Benedict XVI took a somber note, lamenting what he called the "trivialization" of sexuality and lack of faith among young people during a vespers' service in St. Peter's Basilica.
China started its Olympic year with a New Year party including fireworks, singing and dancing put on by the organizers of the Summer Olympics.
In Brazil, about 2 million people gathered at Copacabana Beach in Rio de Janeiro, witnessing a fireworks display that lasted nearly 20 minutes. In Sao Paulo, South America's biggest city, local media said 2.3 million people celebrated at the Avenida Paulista , Brazil's financial center.
In Sydney - one of the first cities to celebrate the New Year - one million revelers cheered as fireworks sprayed from the iconic Harbor Bridge.