UK mobile phone operator Hutchison 3G UK has rolled out the Skypephone, a handset designed to simplify use of the Skype VoIP (voice over IP) application.

Hutchison 3G, branded as '3' in the UK, is offering free calls between Skype users through the 3G mobile phone, which goes on sale on. The Skypephone will be released by the end of the year in Australia, Denmark, Hong Kong, Italy, Ireland, Macau and Sweden.

Some mobile phones already support Skype, but volume-based data usage charges typically make the service expensive to use. Skype recommends using its mobile application with unlimited Hutchison 3 data plans or Wi-Fi.

For more mobile phone reviews, news and tutorials, see Mobile Advisor

Hutchison 3G has been offering unlimited Skype calls on its pricier X-Series phones, but the Skypephone is simpler and aimed at the mass market, according to a company spokesman. The phone has a large button with Skype's logo that's used to launch calls and IMs.

Hutchison 3G is not charging for the cost of Skype calls on its network, although it does limit the service to about 4,000 minutes per month. Hutchison 3G will then suspend outgoing Skype calls but allow incoming ones.

If a user is outside of Hutchison 3G's network, roaming charges apply, which can be pricey despite a rate drop from operators after warnings from the European Commission earlier this year. The Skypephone is dual-band and won't work in the US.

Hutchison 3G's Skypephone allows free calls between registered Skype users, but the SkypeOut service that allows PC users to call regular telephone numbers using Skype is not available. Those must be dialled as regular calls charged for by Hutchison 3G.

The candy-bar style handset, which comes in white and black, was developed by Hutchison 3G and Qualcomm. It has a 2Mp (megapixel camera), MP3 player, Bluetooth connectivity, 16MB of internal memory that can be expanded to 1GB with a Micro SD memory card.

In the UK, the handset costs £50 for customers who prepay their service. The phone is free for those on a contract with Hutchison 3G, which start around £12 per month.

Skype, which is owned by eBay, and Hutchison 3G, agreed in 2006 to work on a mobile VoIP phone. Hutchison 3G is the smallest UK operator and has shown less aversion to shaking up the market, particularly with VoIP, which threatens operators' revenue, wrote John Delaney, principal analyst at Ovum.

"The bigger operators, such as Vodafone, T-Mobile and Orange, have all taken flak recently for alleged hostility towards customers using VOIP on their networks," Delaney wrote. "Now here comes Hutchison 3G, not only encouraging its customers to use VOIP, but bending over backwards to make it easy for them."