Skype launched an updated version of its internet telephony software yesterday, adding call forwarding and personalisation options to its popular VoIP (voice over IP) service.

Skype’s update is currently only available for Windows users, although the company says it is working to bring the new features to its Mac, Linux and Pocket PC editions.

Version 1.4 of the software, which launched for beta testing in August, allows users to forward incoming calls to another Skype name or to other landline or mobile numbers. Calls forwarded to other names using the service are free; calls sent to traditional phone numbers are changed at SkypeOut rates, which start at €0.017 per minute.

The new version also introduces ‘Personalize Skype’, a customisation service being managed by Qpass, a Seattle-based Skype partner. This offers customers pictures to use as avatars and sound clips that can be used as ringtones or to replace the default sounds.

Most pictures and sounds cost €1, although a limited number are available for free.

Qpass will handle content acquisition and billing for Personalize Skype. The firm’s list of customers taking advantage of its add-on ringtones, images and mobile games offerings include Cingular Wireless, T-Mobile International, Vodafone and Sprint Nextel.

Earlier this month, Skype, which is based in Luxembourg, agreed to be acquired by eBay for around £1.47bn in cash and stock. The companies expect the deal to close by the end of the year. Skype advertises a registered user base of 56 million, with more than three million people simultaneously connected to its service at any given time.