Apple was expected to unveil a next-generation iPhone and possibly provide a glimpse of long-absent chief executive Steve Jobs as it kicked off a software developers conference later in the day in San Francisco.
The maker of iPods, iPhones, and Macintosh computers has remained tight-lipped as usual about what announcements it has in store, but speculation and rumour are rampant.
Phil Schiller is a senior vice president of worldwide product marketing at Apple and is filling in for Jobs at the keynote presentation opening the Worldwide Developers Conference. He went on stage in place of Jobs at a Macworld conference in San Francisco in January after Apple's renowned 54-year-old chief went on a leave of absence for health reasons.
Apple has been notoriously secretive about Jobs's health since he underwent an operation in 2004 for pancreatic cancer but has been adamant that he is returning to the company's helm this month.
Apple's keynote speech today is to be tailored to an audience of software developers interested in crafting programmes to work with the iPhone or Macintosh operating systems.
The annual conference provides software developers with technical information about Apple operating systems and opportunities to get hands-on lessons from the company's engineers.
The third-generation iPhone is expected to have improved processor, camera and video capabilities and to allow users to run multiple applications simultaneously.
The ability to run multiple programmes at once is the much-touted feature of the Palm Pre smartphone which went on sale in the US at the weekend and has been praised by reviewers as a worthy competitor to the iPhone.
There has also been unconfirmed speculation that Apple is working on a low-price iPhone.
