[weath]

Get an unlocked, cheap cell phone for use overseas (probably easier/cheaper to get when you get to your destination. Most other countries sell unlocked GSM phones everywhere). Then, get a Skype account and a Skype number (with US number), and buy SkypeOut minutes. Finally, forward your US phone to your Skype number, and set Skype up to immediately forward calls to your "new" pre-paid local number.

1. Why Skype in the middle? Because most US carriers won't allow you to forward calls to an overseas number.
2. Skype calls to overseas numbers are usually cheaper than your carrier.
3. May work with other similar services (ie: Gizmo).
4. Costs are incurred only as you recieve calls.
5. Still have data on your BB (if you want).
6. SIGNIFICANTLY cheaper local calls. No Roaming charges from your US carrier.