Jobs at the Apple event in San Francisco on Wednesday. (AP)

San Francisco, Sept. 9 (AP): Apple Inc CEO Steve Jobs returned to his showman role today, taking the stage at a product launch event for the first time since his nearly six-month-long medical leave.

Jobs, who had a liver transplant this spring, got a standing ovation. Looking thin and speaking quietly and with a scratchy voice, the 54-year-old CEO told the audience he had received the liver of a young adult who died in a car accident.

He urged everyone to become organ donors. “I wouldn’t be here without such generosity,” Jobs said. He had not appeared at such an event since last October. Jobs bowed out of his usual keynote at the year’s largest Mac trade show in January and went on leave shortly thereafter.

At an event for journalists, bloggers and software partners in San Francisco’s convention centre, Jobs announced updates to Apple’s iTunes and iPhone software before ceding the stage to Jeff Robbin, who demonstrated the new iTunes 9 features.

The CEO returned later to unveil a new iPod Nano with a built-in video camera, sound recording and speaker.

Apple also announced price cuts to existing iPod Touch models — $199 for an 8GB model, or $30 less. Apple kept prices constant for its other larger models, but will double the storage space; it will now sell a 32GB version for $299 and a 64GB model for $399.

Jobs disclosed in August 2004 that he had been diagnosed with — and cured of — a rare form of pancreatic cancer called an islet cell neuroendocrine tumour. Last year, he appeared increasingly thin, sparking speculation that his cancer had returned.

On January 5, 2009, Jobs said he had a treatable hormone imbalance and that he would continue to run the company. He went on leave the following week, saying his medical problems were “more complex” than he had thought. Jobs returned to Apple headquarters part-time at the end of June.

The new Nano unveiled today also has a built-in microphone, a pedometer, a 2.2-inch display and an FM radio tuner. It comes in rainbow colors and costs $149 for an 8GB version or $179 for a 16GB model.

Other changes to the iPod line include a beefier iPod classic, which now has a 160 GB hard drive for the existing $249 price. Apple also added brightly coloured iPod shuffles and a smaller, less expensive version of the shuffle — $59 for a 2 GB model.

Meanwhile, the new version of iTunes cleans up the design, gives people more control over what content gets synched — or loaded on — to iPods and iPhones and introduces a way to organise applications purchased for the iPhone and iPod Touch.