Skype is expanding upon its existing partnership with Facebook by introducing the ability to make video calls to your friends on the social network from within Skype itself. The feature is a natural extension of the Skype-powered Facebook-to-Facebook video calling functionality introduced in July, although for now it remains in testing as part of the latest beta release of Skype's desktop client.

Both Skype 5.7 Beta for Windows and Skype 5.4 Beta for Mac include the new feature, which will be available to users who choose to link their Facebook and Skype accounts. Up until now it was only possible to chat with Facebook friends through Skype's instant-messaging feature, in addition to seeing your Facebook wall, updating your status and making comments from within the Skype interface.

Besides the new Facebook video calling feature from within Skype, the latest beta includes improved rendering for a smoother video experience. Also, Windows users with a Premium subscription now get the Group Screen Sharing feature, which was previously only available to Mac users.

Skype's partnership with Facebook has extended the service's reach considerably -- Facebook has more than 800 million users worldwide -- and is another step in their goal of simplifying Internet-based communication. This synergy is also giving Microsoft a major foothold in the growing market for Internet telephony services. The latter finished its $8.5 billion acquisition of Skype last month and owns a small stake in Facebook.