"The iPhone phenomenon is going to stimulate the adoption of smartphones. It will change the landscape, the way the iPod did for the MP3 player industry," said Charles Guo, analyst at JPMorgan.
Analysts expect the new iPhone to draw as many as 10.5 million buyers worldwide this year, and with 6 million of the older devices already in use, help Apple beat its target of selling 10 million devices by the end of 2008.
Most carriers subsidise the phone, tie it to their networks and lock consumers into long-running contracts - something that may have to change to boost its appeal for customers who prefer pre-paid offers.
"Opening it up to prepay outside North America is very important . prepaid is the tariff of choice for most people in most parts of the world," CCS Insight analyst Shaun Collins said.
Outside one Brussels store, where the iPhone is sold unlocked and without a contract beginning at 525 euros (419 pounds), a queue, all men, was steadily building an hour before opening time on Friday.
Germain Merinero, a European Commission employee, at the head of the queue said he was not put off by the price.
"It's a little toy and you pay what you have to," he said.
But a midnight launch in Helsinki, the home turf of the world's biggest mobile phone maker Nokia, drew a scant crowd, while outdoor bars nearby were booming with business.
TASTE OF THE ACTION
The next-generation iPhone is Asia's first official taste of the touch-screen device previously available only in the United States and Europe.
The new iPhone offers faster Web access than the first and supports third-party software like games and instant messaging. Its email capability squarely targets Research in Motion's Blackberry.
Many analysts doubt the device will be popular among mainstream customers in Japan, Asia's largest retail market, because it does not support television services or electronic payment features widely used in the country.
Others point to a vibrant grey market for fakes or unlocked phones - hacked to work on other carriers' networks - in China and southeast Asia, cannibalising demand.
Outside of London's Apple store, not everyone was infected by the hype or even aware of the launch. Looking at the hubbub surrounding the store, one passerby commented: "What's the big deal?"
