rejected Google Voice app, if you're out of WiFi range but still have voice service then Vonage Mobile will redirect your international call (entered directly into the App or selected from your address book) to a local access number in the US -- you're then using your AT&T minutes while being charged Vonage Mobile's discounted worldwide calling rates. The app is strictly pay-as-you-go for the moment and will not give free global calling to those who subscribe to Vonage's $25 per month Vonage World plan -- Vonage says that will come before the end of the year. The Vonage Mobile app for BlackBerry only works over your carrier's voice network while the iPod touch app only works over WiFi, naturally. Also, BlackBerry users will revert to Vonage's lower rates anytime they make an international call whereas iPhone users must launch the Vonage application first.
[Thanks, Ricky B.]