Did you check Roam4free?
Welcome to Roam4free.ie - The end of sky high roaming charges !
Their website says:
Use in over 115 countries, and receive calls for FREE in over 65 countries. No call set up. Per-minute billing. Up to 90% discount on standard mobile rates. Works on most mobile phones and virtually any network across the globe. Easy to use. Top up from anywhere at anytime - direct from your phone. No line rental. No minimum contract. No call set up. No hidden costs.
Here are the Calls Rates for Brazil:
Receive a call (EUR per min): 0.09
Make a call to most destinations (EUR per min): 0.50
SMS Rates
Receive SMS (EUR per SMS): Free
Send SMS (EUR per SMS): 0.35
Other services Rates
Customer care (EUR per min): 0.45
Add credit: Free
Check balance: Free
I admit that I don't understand well the global roaming. But their boss has an interesting VoIP blog (
Roam4free) that I read regularily. So I found the company.