Apple chief executive Steve Jobs on Wednesday revealed the culture-changing company's latest must-have device, a touchscreen tablet computer annointed the "iPad."

"We want to kick off 2010 by introducing a truly magical and revolutionary product," said Jobs, who underwent a liver transplant last year and was making just his second public appearance since September.

The long-awaited iPad has a 9.7-inch (24.6-centimeter) color screen and resembles an oversized iPhone. It is 0.5 inches (1.3 cms) thick, weighs 1.5 pounds (0.7 kgs) and comes with 16, 32, or 64 gigabytes of flash memory.

The cheapest iPad model, with Wi-Fi connectivity and 16GB of memory, is 499 dollars while the most expensive -- which includes 3G connectivity and 64GB of memory -- costs 829 dollars.

"I think it's a home run," said Gartner analyst Van Baker. "It becomes a viable alternative to a netbook and I get the 140,000 applications in the App Store. It is a pretty compelling value."

Apple said it would start shipping the iPad, which has a virtual keyboard but can also be hooked up to an external keyboard, within 60 days, making them available worldwide in late March.

The 3G version will reach the market in late April.

Dressed in his trademark blue jeans, black turtleneck and sneakers, Jobs appeared on stage at the Yerba Buena Center for the Arts Theater to unveil a product that had been the subject of months of speculation.

Walking around the stage or sitting on a couch, he showed off iPad features which include browsing the Internet, doing email, working with spreadsheets and charts, playing videogames, listening to music or watching video.

Jobs, who appeared thin but healthy, said Apple was launching an online "iBookstore" for the iPad and touted its abilities as an electronic reader of books, newspapers and magazines.

"You can have black-and-white, color, video in your books -- whatever the author wants," he said. "We think the iPad is going to make a terrific e-book reader, not just for popular books but for textbooks as well.

"Amazon has done a great job of pioneering this functionality with the Kindle," Jobs said. "We are going to stand on their shoulders."

The legendary Apple CEO said the iPad has support from five of the biggest publishers in the world and that Apple will "open the floodgates for the rest of the publishers starting this afternoon."

Some technology analysts expect the iPad to pose a challenge to other e-readers while a number of publishers are counting on the device to sell digital versions of their publications.

The New York Times, Time magazine and National Geographic were among the partners whose content was displayed on the device on Wednesday.

Apple said that besides serving as an e-reader, the iPad runs all of the applications available through the Apple App Store for the iPod and iPhone.

"If you are thinking about buying a Kindle, you are probably reconsidering that decision. If you are a developer, you have one more reason to develop applications for Apple," said Interpret analyst Michael Gartenberg.

Apple simultaneiously released a kit for software developers to tailor applications for the iPad.

Jobs said he expected the device to carve out a place between the laptop computer and the smartphone.

"Do we have what it takes to establish a third category of products in between a laptop and a smartphone?" he asked. "We think we've done it."

Jobs said the iPad is "so much more intimate than a laptop and so much more capable than a smartphone."

He said it has about 10 hours of battery life. "I can take a flight from San Francisco to Tokyo and watch video the whole way on one charge," Jobs said.

"In general it was a hit," said analyst Rob Enderle of Silicon Valley's Enderle Group, although he expressed some doubt about the inadequate wireless network of telecom carrier AT&T.

"I think this is disruptive for a lot of markets," Enderle said.

"I have a hard time believing after seeing this that folks are going to want an e-reader that just does plain text and doesn't do format or color," he said.

Enderle believed iPads could "do some severe damage" to the gaming market, initially to hand-held gaming systems then eventually to videogame consoles.

"I think the iPad is going to do well for them," said NPD Group analyst Ross Rubin. "I wouldn't want to be a competitor in this space at this point in time."

Apple shares closed 0.99 percent higher at 207.98 dollars.

related report
Facts and figures on the new Apple iPad
These are the principal features and pricing of the new "iPad" touchscreen tablet computer unveiled by Apple chief executive Steve Jobs here on Wednesday:

-- about the size of a piece of paper, the iPad is 0.5 inches (1.3-cm) thick and weighs 1.5 pounds (0.7 kilograms). It has a color 9.7-inch (24.6-cm) LED-display screen that allows for viewing video in high-definition

-- 16, 32 and 64 gigabytes of flash memory

-- a 16-gigabyte Wi-Fi version will be available in late March worldwide for 499 dollars. The 32GB Wi-Fi model will cost 599 dollars while the 64GB Wi-Fi model will cost 699 dollars

-- iPad models equipped with Wi-Fi and 3G will be available in late April in the United States and selected countries. The 16GB model will cost 629 dollars, the 32GB will cost 729 dollars and the 64GB model will cost 829 dollars

-- battery life of up to 10 hours from a single charge

-- runs almost all of the over 140,000 applications for the iPod Touch and iPhone available in Apple's App Store

-- an online "iBookstore" to complement the iTunes music store. iPad syncs with iTunes so applications and content downloaded from the App Store, iTunes Store and iBookstore will be automatically synced to a user's iTunes library

-- a virtual touchscreen keyboard and the ability to hook up an external physical keyboard

-- iWork, a productivity suite of applications for creating presentations or working with spreadsheets and charts

-- powered by A4, a next-generation chip which Apple said provides exceptional processor and graphics performance

-- a Software Development Kit for iPad developers to create applications