With the launch of Skype integration, Truphone’s mobile VoIP service is fast becoming a unified client for other VOIP and messaging services. As well as the ability to make low-cost calls over Wi-Fi or GSM networks and send cheap SMS, it is now supporting Skype and other messaging services via its application for the iPhone or iTouch. The software comes out on Jan. 12, at which point you’ll be able to make and receive Skype calls and IM to other Skype users. Truphone has also added full two-way instant messaging over MSN Messenger, Yahoo! Messenger and Google Talk on the iPod touch as of now and on Jan. 12 for the iPhone. Admittedly you can already use Fring or Nimbuzz iPhone apps to access Skype, but neither of these also integrate VOIP or GSM voice calls as seamlessly. Truphone has already added Twitter integration.