Apple's iPhone 5 hit stores around the world, with long queues forming outside shops in London, Sydney, Tokyo, Paris and New York.
The latest Apple gadget became available from 8am in the UK today, as hundreds were cheered into the brand's store in Covent Garden, central London.
Apple store workers dressed in blue T-shirts formed a passageway and high-fived customers who had been waiting outside the shop for up to a week.
The phone is already guaranteed to be a best-seller, with the company reporting pre-orders around the world of two million in just 24 hours - double the first-day sales of the previous iPhone 4S.
Many customers are not expected to receive theirs until October.
IT businessman Ryan Williams was the first person in the queue and said the atmosphere as he picked up the phone was "crazy".
Williams, 22, from Swanley in Kent, had been camping out in Covent Garden for a week with his friend Peter King.
But the pair were not doing it just for their love of tech - Mr Williams auctioned off the first iPhone to hit the UK's streets to raise £1,000 for charity.
He said: "I didn't expect that kind of entrance to be honest with you, I thought I was just queueing for a phone but it was absolutely mad.
"It was a crazy thing to queue here for a week but it was really good fun, I would definitely do it again, we've raised so much money for Cancer Research UK as well which is absolutely fantastic.
"I was just trying to utilise the fact that there's so much publicity around iPhone queueing, so if we could build on that and raise money for charity at the same time, we were doing it for a good cause."
The new phone, which is thinner and lighter than previous models and can use the newly-announced 4G network, costs from £529, with the 32GB model selling for £599 and the 64GB version costing £699.
It has a larger, 4-inch screen and also comes with a number of software updates, including Apple's new in-house maps feature.
The iPhone 5 went on sale across Asia with mobile carriers reporting record demand, leading at least one to question Apple's supply capacity.
Apple has booked more than 2 million pre-orders for the device in the first 24 hours, double the first-day sales of the previous iPhone 4S.
Masayoshi Son, president of Softbank, one of the two Japanese carriers selling the phone, said he was concerned that Apple does not have enough production capacity to meet demand.
Softbank and Singtel, Singapore's biggest mobile phone operator, said demand for the iPhone 5 had exceeded previous offerings from Apple, partly because the new phones could work on 4G networks that offered much faster data speeds.
KDDI, the other Japanese carrier offering the iPhone, said that it had already run out of the new phone.
Australia's Telstra reported online pre-orders sold out in a record 18 hours and said it was discussing bi-weekly restocking with Apple.
Apple's rival and component supplier, Samsung, stepped up its legal challenge over key technologies, saying it planned to add the new device to existing patent lawsuits against its U.S. rival.
South Korea's Samsung and Apple are locked in a patent battle in 10 countries and the stakes are high as the two vie for top spot in the booming smartphone market.
Both companies are also raising marketing spending to promote their latest products ahead of the holiday sales quarter.
Not everyone has been impressed with the standard of the new technology.
The new maps feature has been criticised by some users for a number of geographical errors, missing information and a lack of features.
Kim Tudo, a student at the University of New South Wales who queued overnight, said he was disappointed the turn-by-turn navigation feature under the iOS 6 mobile operating system behind the new phone was not immediately available in Australia.
James Vohradsky, a 20-year-old student in Hong Kong, said the lack of mobile payment chip was also "a bit of a letdown".
Apple did not embed Near Field Communication (NFC) technology used to turn mobile phones into mobile wallets into the iPhone 5.
Tudo and Vohradsky were less bothered by Apple's decision to drop the wide dock connector used in the company's gadgets for the best part of a decade in favour of a smaller one, a move that some critics have noted adds to costs for users who will now have to buy an adaptor for speakers or other accessories.
The iPhone is Apple's highest-margin product and accounts for half of its annual revenue.
Apple has said it will make initial deliveries of the iPhone 5 at the end of this week in the United States and most of the major European markets, such as the UK, France and Germany.
The phone then goes on sale on September 28 in 22 other countries.
Apple plans to sell the new phone in 100 countries by the end of the year, ramping up competition in a smartphone market that has already reached a fever pitch.
Apple is up against phones that run on Google's Android software, which has become the most-used mobile operating system in the world, while Samsung has taken the lead in smartphone sales.
Samsung has released new ads mocking Apple fans queuing for the new iPhone, showing users favourably comparing the features of Samsung's top-selling Galaxy S3 smartphone.
Apple co-founder Steve Wozniak, in town for a business forum, was among a crowd of several hundred lining up for an iPhone 5 in sub-tropical Brisbane.
"I just feel this impulse, like I want to be part of this big adventure, this big revolution and this advance in technology," Wozniak, who stopped working for Apple in the late 1980s, said.