Jobs kicked off a theatrical press event in downtown San Francisco by poking fun at persistent rumors about his health.

He flashed a famous Mark Twain quote, "The reports of my death are greatly exaggerated," on the screen as he stepped onstage.

"Enough said; the real topic of today is music," Jobs began.

The iconic Apple pitchman's medical condition has been the subject of considerable debate since he appeared gaunt at a conference in June.

New products announced by Jobs include high-definition television shows available on Apple's online iTunes store and a slim new iPod Nano model that upgrades the technology while returning the gum stick shape people preferred.

Jobs also showed off an upgraded iPod Touch model made slimmer than the original version and with a built-in speaker.

The iPod lineup combines feature upgrades with price cuts of as much as 100 dollars on higher end models.

IPod Touch models with 32 gigabytes of memory are priced at 399 dollars while a 16-gigabyte version will sell for 299 dollars and an eight-gigabyte Touch for 229 dollars.

Jobs cited statistics showing iPods command nearly 74 percent of the MP3 market and said that more than a hundred million applications for iPhones and iPod Touch models have been downloaded since the "App Store" opened 60 days ago.

He also addressed concerns about iPhone 3G performance problems by saying a free iPhone 2.1 update will be released on Friday to fix the troubles.

"It's a big update," Jobs said of the iPhone software release. "It fixes a lot of bugs. You will get fewer call drops ... You are not going to get some of the crashes and other things that we've seen."

Apple's ceaseless modifying of iPod models also makes them a moving target for competitors such as Microsoft, which has a fourth-place 2.5 percent of the MP3 market with its Zune devices.

"Apple is a force to be reckoned with," Gartner analyst Van Baker said while toying with iPods in a demonstration room after the presentation by Jobs.

"They have the market covered from the 50-dollar price point to the 400-dollar point."

Apple incorporated motion-sensing "accelerometer" technology from its iPhones and iPod Touch models into the new Nano, which adjusts screens to how the devices are held and lets people shuffle music with "a shake."

"You just take your iPod, shake it and it's shuffled," Jobs said, flicking his wrist to demonstrate and his Nano jumping to a Dean Martin song.

Analysts were unfazed by the fact Apple stock price slipped despite the strong iPod line-up, dropping nearly four percent to 151.68 dollars per share in afterhours trading.

"They've fairly staked out the segment of the market; introduced some new features to keep making a mature product fresh and interesting," said NPD analyst Ross Rubin.

Along with being the thinnest iPod that Apple has ever made, the new Nano is made with toxin-free components and is primarily recyclable aluminum and glass, Jobs said, addressing concerns by critics of Apple's environmental record.

Jobs touted iPod Touch as the best portable device for listening to music or watching videos.

"Now you can make a pretty good argument for it being the best portable device to play games on," Jobs said, noting that more than software for more than 700 games is available at the App Store.

The motion-sensing feature of iPod Touch allows the device itself to be used as a controller with tilting or twisting movements.

Apple reports selling more than 160 million iPods since the first model was introduced in late 2001. The iTunes store has become the top music seller in the United States.

Proof of Apple's clout is seen in NBC Universal's return on Tuesday to the iTunes fold. NBC had reportedly pulled its television shows from iTunes in a bid to pressure Apple to charge more for programs.

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