Microsoft has launched a phone called the Kin aimed at younger users and geared towards social networking.
The software firm says the phones have been created specifically to help people who like to stay in touch with friends and share content.
Fitted with a high-resolution camera, the phone is also the first to access Microsoft's Zune music service.
The launch is designed to counter rivals such as Apple, Google and Research In Motion's Blackberry.
Made by Sharp, the two Kin handsets will go on sale in the US in May. In Europe, the Kin models will be available on the Vodafone network and will be launched in Autumn 2010. No prices have been given for the phones.
"This is a phone that knits together a tight community of kindred spirits..., the phone personifies true kinship between people, technology, friends and customers," said Robbie Bach, president of the entertainment and devices division at Microsoft.
Both phones have a multi-touch screen and a slide-out keyboard. The home screen of the device is always on and shows the latest events, such as text messages, tweets, or shared images, happening among someone's group of friends
The phone has an area dubbed the "spot" onto which owners can drag content, such as videos, and then decide how to share it and who to share it with.
Also, anything created on the phone is mirrored online and organised into a timeline and can be accessed from any web browser.
"Social is the DNA of this phone," said Microsoft's Derek Snyder, one of the product marketing managers who worked on its development. "Social is the fabric of this experience."
The Kin marks a departure for Microsoft which has typically offered its software to phone makers. With Kin it will have control over both hardware and software.
According to research firm Canalys, Microsoft's software currently has about 9% of the smartphone market. That puts it fourth in the global market behind Symbian, Rim and Apple.
In early 2010, Microsoft launched the latest version of its mobile phone operating system, called Windows Phone 7 series.
It will replace Windows Mobile. The next OS will integrate the company's other products including its Bing search engine, Zune media marketplace and Xbox Live video-game network.
