Microsoft on Monday set out to win over iPhone and Android gadget devotees with Windows 8 smartphones, new devices that emphasize individualism and unify digital lives in the Internet cloud.

The global rollout of Windows 8 phones, set to begin in Europe this weekend, is the final piece in a Microsoft operating system transformation aimed at harmonizing the technology titan's software and hardware for mobile lifestyles.

"It has been for us an exciting and energizing few days," Microsoft chief executive Steve Ballmer said while unveiling the slick new smartphones at a media event in San Francisco.

"Windows PCs (personal computers) really are the best PCs ever and today we are bringing phones into the Windows family with Windows 8."

Microsoft on Friday launched its latest generation Windows operating system, hit the market with Surface tablet computers and opened scores of temporary "pop-up" stores that have drawn crowds interested in Windows 8 devices.

"The lines we've seen at Microsoft stores have been heartening," Ballmer said.

Windows Phone 8 is the final component in Microsoft's new equation and shares a user interfaced based on "tiles" that can be personalized with people's pictures, applications, games, music and more.

Microsoft corporate vice president Joe Belfiore said that Microsoft was out to "re-invent" a smartphone experience that has for years basically consisted of a locked screen that opens to rows of icons.

"We decided not use that tired old metaphor and came up with our own way that puts people at the center of the experience," Belfiore said with a slight jab at iPhone.

Microsoft's online shop is stocked with more than 120,000 applications tailored for Windows 8 phones and the number is growing, according to Belfiore.

Analysts have long contended that hip, fun, or functional "apps" are crucial to the success of smartphones.

Microsoft partnered with Facebook to optimize a Windows 8 version of the leading social network's application that includes serving up slide shows of personal pictures to handset lock-screens.

A "live apps" feature allows for sports scores, messages, images or other data to be streamed to an ever-changing lock-page on phones, a demonstration showed.

A Twitter application was also tailored with Windows 8, and a specially designed Skype "app" is in the works, according to Belfiore.

Data Sense lets users easily control how much information is flying across telecom networks in order to avoid potentially punishing overage charges from carriers.

Belfiore brought his three young children on stage to demonstrate Kid's Corner, the ability to create a playground on a smartphone where wee ones can tinker.

"I think it's awesome," actress Jessica Alba said of Kid's Corner. "You're kid is not going to get into your stuff and do what they do best, which is create chaos, good chaos, but chaos."

She shared a story of her daughter at age two playing with her mobile phone and sending a gibberish message to Alba's millions of Twitter followers.

"I love that I can curate the content," said Alba, who told of switching from an iPhone to a Windows 8 phone. "It is a clutch feature. My daughter is totally into it."

Ballmer touted the ability to personalize Windows 8 phone screens with apps, images and data to make devices "uniquely yours" by "pinning" tiles.

He also highlighted how people Microsoft's Internet "cloud" storage service SkyDrive could be used to synch everything from Word documents to music across phones, personal computers, and Xbox 360 videogame consoles.

"They all share the same iconic look and feel, and they will update as the world around you changes," Ballmer said.

Ballmer also provided glimpses at "killer hardware" that included Nokia, Samsung and HTC handsets with big screens and sleek lines.

Windows 8 smartphones will roll out around the world in November and December.

"My phone is really an extension of me as a person," Alba said. "From work that I do to music I like to listen to, it is really personal on the Windows phones. My phone is different from everyone else's, and I like that."