The iPad, which is larger in size but similar in design to Apple's popular iPhone, was billed by CEO Steve Jobs on Wednesday as "so much more intimate than a laptop and so much more capable than a smart phone."
Jobs, 54, a survivor of pancreatic cancer who got a liver transplant during a 5 1/2-month medical leave last year, looked thin as he introduced the highly anticipated gadget.
The iPad has a 9.7-inch touch screen, is a half-inch thick, weighs 1.5 pounds and comes with 16, 32 or 64 gigabytes of flash memory storage. The basic iPad models will cost $499, $599 and $699, depending on the storage size.
All models have Wi-Fi and Bluetooth connectivity built in. Jobs said the device has a battery that lasts 10 hours and can sit for a month on standby without needing a charge.
Apple will also sell a version with pay-as-you-go data plans from AT&T in the U.S. Two tiers of data plan will be available without contracts: $14.99 per month for 250 megabytes of data, or $29.99 for unlimited data usage.
Those 3G models will cost more - $629, $729 and $829, depending on the amount of memory. The Wi-Fi only version will be available worldwide in March, and the 3G version in April. International cellular data details have not yet been announced.
Apple had kept its "latest creation" tightly under wraps until Wednesday's unveiling, though many analysts had correctly speculated that it would be a one-piece tablet computer with a big touch screen, larger than an iPhone but smaller than a laptop.
The CEO demonstrated how the iPad is used for surfing the Web with Apple's Safari browser. He typed an e-mail using an on-screen keyboard and flipped through photo albums by flicking his finger across the screen. And he showed off a new electronic book store, putting the iPad in competition with Amazon.com Inc.'s Kindle and other e-book readers.
Jobs said the iPad will also be better for playing games and watching video than either a laptop or a smart phone. The iPad comes with software including a calendar, maps, a video player and iPod software for playing music. All seem to have been slightly redesigned to take advantage of the iPad's bigger screen.
Tablet computers have existed for a decade, with little success. Jobs acknowledged Apple will have to work to convince consumers who already have smart phones and laptops that they need this gadget.
"In order to really create a new category of devices, those devices are going to have to be far better at doing some key tasks," Jobs said. "We think we've got the goods. We think we've done it."
Applications designed for the iPhone can run on the iPad. Apple is also releasing updated tools for software developers to help them build iPhone and iPad programs.
"We think it's going to be a whole 'nother gold rush for developers as they build applications for the iPad," said Scott Forstall, an iPhone software executive.
A new newspaper reader program from The New York Times and a game from Electronic Arts Inc. were also demonstrated during the event. The audience, which included many journalists and bloggers, clapped and even gave Jobs a standing ovation.
Shares in Apple rose $1.84, or less than 1%, to $207.78 in afternoon trading on Wednesday. The Cupertino, Calif.-based company's shares have more than doubled over the past year, partly on anticipation of the tablet computer. Shares in Amazon rose $1.51, or 1.3%, to $120.99.
