I second the suggestion to look at the 8320 and T-Mobile service. I had been a long time at&t /Cingular customer and switched to T-Mobile on a 30-day trial. With their "my favs" package you can call five numbers which don't come out of your plan minutes, and the WiFi connection at home I don't come close to using my plan minutes.

I was skeptical about T-Mobile's coverage area until I was in San Jose and a co-worker on at&t was not able to get calls in the Convention Center, and I had no issues.

I've read on some forums that when you are out of the country but on Wi-Fi you are not charged any roaming for your calls. On Wi-Fi it does use your cell plan minutes (unless you have the @home option, when any Wi-Fi calls are unbilled).