More details on the PSP voice-and-video call partnership between BT and Sony, reported in May, were announced at the Leipzeig Games Conferences today. BT has written VoIP software called Go!Messenger that will enable free video calls, voice calls and instant messaging over a wireless network. The software can be downloaded online or shared between users and will enable a range of free and paid calls out to fixed-line and mobiles using a headset, while there will be a Go!Cam video camera for video calls. The service will be available first to UK, France, Germany, Spain and Italy and BT plans to offer the software wholesale to other wireless telcos. With 8.5 million European PSP users, BT and other telcos will hope the computer-to-phone calls will provide some additional revenue.