Sony Ericsson, The fifth largest mobile phone maker, has announced a deal with online music publisher, PlayNow Plus that will create the first Walkman phone capable of providing users with unlimited access to their favorite music without any copyright restrictions.

Sony Ericsson will team up with mobile music subscription specialists, Omniphone, for its PlayNow Plus service which will also provide users with an option to pay-as-you-go format. The PayNow Plus deal will enable users to have unlimited access to the five million, or so, DRM-free tracks. This breadth of music is significantly more than what Nokia can offer and is beginning to get closer to the eight million tracks now available within Apple's iTunes library.

The deal is seen as a preemptive move by Sony Ericsson to challenge mobile rival Nokia who are to release their touchscreen mobile phone on October 2. The new Sony Ericsson phone is scheduled to launch in Telenor, Sweden on a special edition of the W902 Walkman phone. Other countries and operators are no doubt waiting in the wings.