Apple Inc. CEO Steve Jobs applauds at the conclusion of the launch of the iPad 2 on stage during an Apple event in San Francisco, California March 2, 2011. [Photo/Agencies]

SAN FRANCISCO -- Apple CEO Steve Jobs briefly emerged from his medical leave and walked on stage to a standing ovation Wednesday to unveil the second generation of the popular iPad. It comes with two cameras and will go on sale worldwide later this month.

Jobs looked frail as he appeared in his signature black mock turtleneck, blue jeans and wire-rimmed glasses.

"We've been working on this product for a while, and I just didn't want to miss today," Jobs told an audience that included bloggers and Apple enthusiasts. "Thank you for having me."

The Apple iPad 2 is shown during its launch event in San Francisco, California March 2, 2011. [Photo/Agencies]

The next-generation tablet computer is faster than the original iPad's. As expected, it comes with two cameras for taking photos and video chatting. The battery life will be the same as the original, about 10 hours of usage or a month on standby.

The iPad 2 is also thinner, 8.8 millimeters, or about a third of an inch, instead of the current 13.4 millimeters.

"The new iPad 2 is actually thinner than your iPhone 4," Jobs said.

The original iPad, which went on sale last April, was more popular than analysts anticipated. Apple sold 15 million in nine months.

The iPad was initially used for checking e-mail, surfing the Web and watching online video. But as the number of software applications, or "apps", designed just for iPad grew, the tablet made itself at home in offices, shops, restaurants and countless other settings.

The rush for iPads sparked dozens of copycat touch-screen devices, but so far, none has broken into the mainstream consciousness the way the iPad has. In February, Motorola Mobility Inc.'s Xoom, the most promising challenger so far, went on sale. It runs a new version of Google Inc.'s Android software that was designed for tablets, not smart phones.