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Apple Inc. CEO Steve Jobs returned Wednesday to the showman role that has helped define his company leadership, taking the stage for the first time since his medical leave to announce such new products as an iPod Nano that records video.

Jobs, who had a liver transplant this spring from a young adult who died in a car accident, got a vigorous standing ovation from many in the audience.

Looking thin and speaking quietly and with a scratchy voice, the 54-year-old CEO urged everyone to become organ donors.

"I wouldn't be here without such generosity," Jobs said.

Jobs had not appeared at such a product launch event since last October. He bowed out of his usual keynote at the year's largest Mac trade show in January and went on leave shortly thereafter for nearly six months.

At an event for journalists, bloggers and software partners, Jobs announced updates to Apple's iTunes and iPhone software and unveiled a new iPod Nano with a built-in video camera.

Phil Schiller, Apple's top marketing executive, also took the stage to announce price cuts and storage boosts to existing iPod Touch models.

Few chief executives are considered as critical to their companies' success as Jobs has been to Apple's since 1997, when he returned to the company after a 12-year hiatus, and Apple's stock has soared and plunged on news and rumors of his health.

Shares in Apple reached a 52-week high of $174.47 in Wednesday trading, then fell to close at $171.14, or $1.79 below Tuesday's closing.

Jobs, whose medical problems began more than five years ago and included treatment for a rare form of pancreatic cancer, seemed happy to be back in the spotlight, saying, "I'm vertical, I'm back at Apple and loving every day of it."

As was expected, Apple's announcements were mainly tied to music players and the iTunes software, though Jobs spoke briefly about the iPhone and said 30 million of the devices had been sold so far.

Apple compared the new video-camera Nano to Cisco Systems Inc.'s Flip Mino, a tiny, simple video recorder that sells for $149, just like the basic, eight-gigabyte version of the overhauled Nano (The 16 GB Nano costs $179). The Nano — the smallest iPod that has a screen — also has a microphone, a pedometer, a 2.2-inch display and an FM radio tuner.

Meanwhile, the new version of iTunes, known as iTunes 9, gives people more control over what content gets loaded on to iPods and iPhones. It lets five computers on the same home network share — by streaming or copying — music, video and other content, a departure from the strict copy protection Apple insisted on in the past.

Michael Gartenberg, a technology analyst with the Interpret market-research firm, said Apple met "reasonable expectations" with its Wednesday announcements.

"If you were expecting an Apple jetpack or an Apple hovercraft, or even an Apple tablet, you didn't get that," Gartenberg said, referring to speculation that Apple was producing a "tablet"-style device resembling a giant iPod Touch.

At the close of the event, Jobs stepped from the stage and lingered for a few moments, chatting with Apple executives and a few fans who surrounded him.

"People see he's alive and well," Gartenberg said. "Had he not shown up, he would have been the elephant that wasn't in the room."