The new Apple iPhone goes on sale across the UK from today, and retailers are already concerned that they will be unable to keep up with demand.
A year ago, Apple launched the first iPhone, which set a design benchmark for the industry with its combination of a mobile phone, music, video player and internet browser.
But a year is a long time in the world of media communications, and Apple has now launched a new, snazzier version of its iPhone.
The new model is intended to be more popular as a business phone thanks to its support for 3G networks and compatibility with Microsoft Exchange email servers, and Apple hopes it will rival RIM's successful Blackberry.
Last year four million Apple iPhones were sold and this year, Apple plans to sell a further 10 million. Blackberry currently has 16 million subscribers, 60 per cent of which are business users.
Although the new Apple iPhone
is competition for the Blackberry, analysts are unsure as to whether it will be able to take any significant market share from RIM, especially as RIM is planning a new Blackberry mobile phone
, similar to the iPhone, due to be released later in the year.
But nevertheless, the iPhone is still predicted to sell out fast, with just a dozen or so models thought to be at each of the UK's 1,300 Apple, O2 and Carphone Warehouse stores.
A message on 02's website said: "We are experiencing unprecedented demand for the device and whilst we are confident that all customers who want iPhone 3G will get one by the end of this summer, initial supply is limited and will be for some weeks."
O2 has said that sales at its stores will be limited to one per customer and two per business customer.
As well as improved business service, the new Apple iPhone also boasts GPS satellite positioning and the 'App Store'; a catalogue of software that can be directly installed to the iPhone – programmes include instant messaging and an eBay
auction tracker, while businesses will be able to create their own programmes for employees' phones.
The new phone will cost between £99 and £159, depending on the tariff, and free for those who sign up for tariffs between £45 and £75 a month.