Apple Watch unveiled

Apple CEO Tim Cook debuts the Apple Watch Sport during a March 9 event at the Yerba Buena Center for the Arts in San Francisco.  (Stephen Lam / Getty Images)

Apple CEO Tim Cook talks about the new Apple Watch during an Apple event on March 9 in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook unveils the Apple Watch during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook interacts with model Christy Turlington Burns during a March 9 event in San Francisco to unveil the Apple Watch.  (Stephen Lam / Getty Images)

The Apple Watch comes with a touch-screen and two side buttons. It must be paired with an iPhone, from where it draws apps and alerts.  (Eric Risberg / Associated Press)

The limited-in-quantity Watch Edition starts at $10,000 and will only be available in certain stores.   (Eric Risberg / Associated Press)

The Watch could be used to hail an Uber car or swipe over a lock to get into a hotel room, among other apps.  (Eric Risberg / Associated Press)

“We think it’s quickly going to become integral to your day,” Apple Chief Executive Tim Cook said in announcing what he described as an 18-hour battery.  (Eric Risberg / Associated Press)

Altogether, the Watch comes in 38 different looks -- 19 of each size.  (Eric Risberg / Associated Press)

The Watch comes in a “strong and beautiful” stainless-steel housing.  (Eric Risberg / AP)

The Watch face can be customized in millions of different ways with different calendar, background image or clock types.  (Eric Risberg / Associated Press)

Visitors look at a selection of new Apple Watches in San Francisco.  (Kay Nietfeld / EPA)

Cook called the Watch, a “coach on your wrist” that would, among other things, notify you if you’ve been sitting too long.  (Kay Nietfeld / EPA)

Apple CEO Tim Cook talks about the Apple Watch during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook talks about the Apple Watch during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Kevin Lynch discusses the Apple Pay feature of the Apple Watch during a March 9 event in San Francisco.  (Eric Risberg / Associated Press)

Apple CEO Tim Cook talks about the Apple Watch during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook talks about the Apple Watch during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

HBO CEO Richard Plepler speaks during a March 9 Apple event at the Yerba Buena Center for the Arts in San Francisco.  (Stephen Lam / Getty Images)

Apple CEO Tim Cook talks about the Apple Watch during a March 9 event in San Francisco.   (Stephen Lam / Getty Images)

Apple CEO Tim Cook talks during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook talks about the iPhone 6 and iPhone 6 Plus during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook talks about Apple TV during a March 9 event in San Francisco.   (Eric Risberg / AP)

Apple’s, Jeff Williams, discusses ResearchKit during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Jeff Williams discusses ResearchKit during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Jeff Williams discusses ResearchKit during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Phil Schiller talks about the new MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Phil Schiller talks about the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Phil Schiller talks about the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Phil Schiller talks about the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s Phil Schiller talks about the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook introduces the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook introduces the new Apple MacBook during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple’s, Jeff Williams, discusses ResearchKit during a March 9 event in San Francisco.   (Eric Risberg / Associated Press)

Apple CEO Tim Cook kicks off the San Francisco event to unveil the Apple Watch on March 9.   (Eric Risberg / Associated Press)

Members of the media and invited guests wait outside of San Francisco’s Yerba Buena Center for the Arts for the start of Apple’s event on March 9.  (Eric Risberg / Associated Press)

An Apple logo is seen on a screen at San Francisco’s Yerba Buena Center for the Arts before the start of a March 9 event to unveil the Apple Watch.  (Stephen Lam / Getty Images)