International teams have built 19 sun-powered homes in Spain's capital for a contest that shows off futuristic designs, including one house that swivels 180 degrees.

In western Madrid's huge Casa de Campo park, the sun glints off the solar panels of a futuristic mini-village erected in 10 days by university teams from China, Japan, Brazil, Egypt and across Europe.

Facebook on Thursday said that it has shaken up its engineering teams to make targeting smartphones a top priority at the world's leading social network.

"We have really just re-organized the company to build faster on mobile," Facebook director of product management Peter Deng said during a briefing with reporters at the company's campus in Menlo Park, California.

A customer in Shenzhen, China, took a brand new laptop out of its box and booted it up for the first time. But as the screen lit up, the computer began taking on a life of its own. The machine, triggered by a virus hidden in its hard drive, began searching across the Internet for another computer.

The laptop, supposedly in pristine, super-fast, direct-from-the-factory condition, had instantly become part of an illegal, global network capable of attacking websites, looting bank accounts and stealing personal data.

Along with a new iPhone 5, Apple unveiled accessories Wednesday that could prove to be a blessing and a curse for customers: a set of earbuds that are meant to fit comfortably in more people's ears, and a new adapter that will be needed to plug the new phone into older car dashboards and speaker systems.

The new earbuds, called EarPods, are being sold separately for $29 but will be included at no extra charge with the iPhone 5 and the refreshed iPod Touch and iPod Nano.

A single Facebook message on a congressional election day in 2010 prompted about a third of a million more Americans to cast their vote, scientists said on Wednesday.

The biggest-ever experiment into social networking confirms that peer pressure in cyberspace helps get out the vote in the real world, they said.

Motor racing is set for an electric makeover that will see a new generation of green cars speeding at 220 kmh (138 mph) around urban racetracks -- at least until their batteries run out.

Alejandro Agag, CEO of Formula E Holdings, says the global championship, which has been authorized by motorsport's governing body the Federation Internationale de l'Automobile, will help finally make electric cars popular.

Apple on Wednesday introduced its new iPhone 5, a lighter, thinner and more powerful version of its iconic mobile device.

"It is an absolute jewel. The software and engineering that went into this product is the most challenging our team has ever taken on," Apple marketing chief Phil Schiller told a packed launch event in San Francisco.

Scientists on Wednesday reported they had invented an invisible tag using the widely-used "quick response" code to help thwart banknote forgers and criminals who sell bogus drugs or fake vintage wine.

The QR code is a square of black and white pixels that can be scanned by a smartphone, which then links to an Internet address.

Facebook founder Mark Zuckerberg said Tuesday the social network giant is focused on mobile devices and should be seen as a smart bet despite a "disappointing" stock market debut.

"It is really clear from the stats and my own personal intuition that a lot of energy in the ecosystem is going to mobile, not desktop (computers)," Zuckerberg said during an on-stage interview at a TechCrunch Disrupt conference in San Francisco.

Tech startup BrandBounty on Monday sought to enlist smartphone users around the world in a "crowd-sourced" battle against knock-off goods and pirated digital content.

The creators of BrandBounty, which launched earlier this year, were at a TechCrunch Disrupt gathering of technology startups in San Francisco to show off an application they designed to transform "consumers into brand vigilantes."