Apple CEO Steve Jobs took the stage at his company's iPod event today, the first time he has appeared in public since October 2008.

Jobs, who received a standing ovation from the crowd of analysts and reporters, said, "I'm very happy to be here today with you all. As some of you know, about five months ago I had a liver transplant, so I now have the liver of a mid-20's person who died in a car crash. I wouldn't be here without such generosity. I hope all of us can be as generous and become organ donors." Jobs then went on to thank the Apple community for its support.

Last January, Jobs took a six-month medical leave , citing "health-related issues [that] are more complex than I originally thought." Reports between then and June, when he returned to work at Apple, said that Jobs had received a liver transplant in April at a Memphis, Tenn. hospital.

Several days later, Methodist University Hospital in Memphis confirmed that Jobs had received the transplant.

Photos from Apple's San Francisco event today provided by several Web sites, including Engadget showed a thin-faced Jobs.

Other reporters on the scene, including Gizmodo's Jason Chen, noted the strength of Jobs' voice. "Steve's voice seems a little bit softer than we remember, a little bit of a hoarse whisper," said Chen on Gizmodo's live blog . "But all in all he seems able-bodied, if still skinny."

Jobs remained on stage to demonstrate features in an update to the iPhone and iPod Touch software, but then ceded the event to other Apple executives.

"I was totally surprised to see him today," said Ezra Gottheil, an analyst at Technology Business Research. "But it's one step toward him getting rid of his absence being a problem, and get rid of the tight scrutiny on every little change in his weight."

There's also the chance, Gottheil added, that Jobs' appearance foretells more than what most analysts had expected from today's event, which has been generally cast as an business-as-usual update of the iPod music player line.

"Or he's there to make a simple software change more exciting," Gottheil speculated.