I dont know if i am way behind,but have you ever come across software for your mobile call FRING.
It makes your mobile into a voip phone to
oops!wrong section,damn i must be tired.
I heard about fring for a while now and now have permanently installed it on my N95.
I use it mostly for MSN and Skype chatting though. I will maybe do a test sometime next week to test it out. Both on wireless and then on 3G. Should be interesting.