In a hoarse voice, he said he had received the liver of a 20-year-old who had died in a car accident.
"I wouldn't be here without such generosity," Jobs said of his health struggles, before moving on to announce upgrades to the technology of the company's wildly popular family of iPods, including the introduction of a much-anticipated video camera in iPod Nano.
His voice gaining strength as he started talking shop, Jobs gave an overview of the company's accomplishments, highlighting that 30 million iPhones have been sold and 75,000 applications are in the App store. Since its launch a year ago, he said users have downloaded 1.8 billion apps from the store.
He said the company will release a free update to the iPhone operating system that will be available for download today.
Moving on to music, Jobs said that iTunes is now in 23 countries, with 100 million credit card accounts.
Announcing iTunes 9, he said the updated and newly designed program allows users more control over what they synch with iPods and iPhones and does a better job of organizing applications for the iPhone and iPod Touch. It also improves music-sharing by letting five computers on the same network share music and video content.
Although he briefly ceded the stage to Philip Schiller, Apple's senior vice president of worldwide product marketing, who announced the iPod updates, Jobs returned to the microphone to unveil one more feature: a highly-anticipated video camera.
Jobs said the video camera would be built into the iPod Nano. He also said the new Nano, which will be available in 9 colors, will have a larger 2.2-inch display, a built-in FM radio, a video recorder and a pedometer. The 8 gigabyte versions will retail for $149 and the 16 GB will sell for $179.
After playing an ad for the new Nano, Jobs welcomed singer/songwriter Norah Jones onstage to perform her hit song "Come Away With Me."
As expected, the company also unveiled updates to the popular iPod Touch model.
Schiller said Apple had reduced the price of the 8 GB iPod Touch from $229 to $199. He also announced price reductions for the higher capacity iPod Touch models.
The iPod Classic, he said, was getting a capacity boost from 120 GB to 160 GB, but with no price change. He also announced new colors for the iPod shuffle: Black, silver, pink, green and blue shuffles will retail for $59. A special stainless steel version will sell for $99.
Rob Enderle, an independent technology analyst, thought Jobs' attendance was the best news that could have come out of the event.
"I really thought the big news was that he was able to get through a long program," he said, adding that Jobs looked full of energy and not as thin as he expected. "It's much more important that Apple gets its CEO back than any single product."
Noting that shares in Apple briefly hit a 52-week high of $174.47 in afternoon trading and then fell to close at $171.14, or $1.79 below Tuesday's closing, Enderle said, "The market's being a little more critical and short-sighted than it should be."