Not quite the answer called for, but for voice comms, get a phone with wifi as in many countries - Northern Spain is the best example - wifi is free and everywhere. France is probably the worst for free wifi but McDonalds always has wifi and you can also hang about outside Apple stores. Oh, and then use Skype.
A second tip is to use phone-network-accessable VOIP, For example dialling 902660044 in Spain connects you to a very cheap VOIP international service. I believe other countries have similar systems.