I know this forum is GSM and I know that most people don't want to buy another phone just to roaming in one country, but here is an interesting offer from MetroPCS:
MetroPCS: Unlimited International Calling For $5 - Yet another pricing bomb dropped on market by carrier - dslreports.com
http://www.metropcs.com/plans/default.aspx
We are talking about $5 on top of the base plans, but they are pure unlimited and they will reflash third party CDMA phones to work on their network. They also have unlimited data plans.
Conversely, MetroPCS doesn't have as strong a network as many of the other players.