Skype, a pioneer in voice over IP (VoIP) software, is bringing a phenomenon from the mobile world to internet telephony.

The maker of the popular VoIP application has done a deal with Warner Music to license all of the songs the record label releases as ringtones.

Skype will sell the 30-second ringtones to customers for $1.50 each, as a way to personalise the tone they hear when they receive incoming calls.

The move will add to the revenues Skype brings in from charging customers to place and receive calls to and from standard phones. Skype's software, which has approximately 75 million users, is free to download.

Ringtones will be available from Warner artists such as Green Day and Madonna within the next two months, with Skype set to promote Madonna as the first 'featured artist' on its online store.