Interesting to see that while Martin Geddes is having a trough of personal disillusionment with VoIP, Deutsche Telekom have decided that VoIP does have value after all, and they've decided to invest money in Jajah.

There are a whole brace of companies right now trying various business models that use VoIP to enhance and reshape what can be done with traditional telephony. For example, Fring and Truphone are bringing VoIP to the mobile handset, iotum bringing IM, presence and VoIP for Blackberry, and a number of companies are selling "travel SIMs" that allow mobile roaming costs to be dramatically reduced, using VoIP backhaul and a clever choice of termination point.

From a traditional telco point of view, Jajah is probably the least disruptive, since it makes calls from the middle (3rd party call control), such that the call endpoints are still traditional phone lines.

I understand that T-Mobile are also using VoIP backhaul to allow free international call minutes to be rolled into mobile talk plans. There's an interesting attitude to VoIP emerging in Deutsche Telekom, very much using the economics of VoIP to work in their own best interests...