Wrist bands range from leather and stainless steel to sports models in hues from pink to blue.
Apple is expected to introduce its first new product since the iPad in 2010, a smartwatch, later on Tuesday.
Has Steve Jobs' handpicked successor inherited the magic touch or is Apple's winning streak coming to an end?
The move marks a significant ramping up of one of Facebook's most closely watched new advertising products, which analysts believe could help the Internet company capture a bigger slice of lucrative brand advertising budgets.
Facebook, which announced the move in a post on its official blog on Wednesday, is working with streaming music services Spotify, Rdio and Deezer to offer the music previews.
Google, which is working on projects including self-driving cars and robots, has become increasingly focused on artificial intelligence in recent years.
Shares of the world's No. 1 online social network soared as much as 15 per cent in extended trading before suddenly falling to $47.40, down 3 per cent from its $49.10 close.
The valuation was more conservative than the $15 billion some analysts had expected for the social media phenomenon, potentially attracting investors who might consider the money-losing company's listing price a better deal, with room to rise.
The eight-year-old online messaging service gave potential investors their first glance at its financials on Thursday when it publicly filed its IPO documents, setting the stage for one of the most-anticipated debuts in over a year.
Shipping will start fall.
The chipmaker's Clover Trail+ mobile chip will be used in one version of its 10.1-inch tablet.
The acquisition is expected to increase Yahoo's audience by 50 per cent.
Apps from CNN, Elle, Tumblr and Evernote are among half-dozen new apps for Glass unveiled during Google's annual developer conference.
His voice is now softer than before, making it difficult to deliver long monologues.
Apple's software is a growing threat to the No. 1 search engine.
Google has stepped up efforts to adapt its business to a rapidly changing technology.
Yahoo Inc's first quarter revenue fell short of Wall Street targets, as the Internet company continued to feel the effects of declining traffic to its Web properties and of falling display advertising sales.
Google Inc Executive Chairman Eric Schmidt predicts that there will be more than a billion smartphones in use featuring its Android software within the next six to nine months.
Mobile ads will account for roughly half of Twitter's advertising revenue this year and will make up more than 60 percent of the company's ad revenue by 2015.
Dailymotion could be valued at roughly $300 million.