Just get a T-Mobile phone here in the US, no data roaming in about 150 countries. We made the switch 2 years ago. In the last 2 weeks I was in Jamaica, Haiti, Dominican Republic and just used my home phone as it I was at home. Calls to the US are 20 cents/minute, local in country calls are more expensive, but I just use Skype on those. You won't get 4g service, but certainly fast and cheap enough.
