What VoIP can do to roaming charges is shown in the US where international calls for both mobile and fixed line are quite cheaper than in Europe. This morning I came across this news here and was quite amazed about it.

I have a special mobile roaming deal that allows me to make "cheap" international mobile calls for 39c per minute. This is about 2-5 times lower than calls with the average mobile operator in Europe.

Now, with Gorilla Mobile you can make calls for only 5cents per minute though. It uses VoIP technology but is only available with a US number and for calls originating from the US. They say it will be available as an app for the iPhone as well soon.