I use a unlocked dual sim quad band phone that doubles as a hot spot or can be teathered.
I have a second international sim card that is pretty reasonable in most countries...
One sim card....
International SIM Card | Prepaid Roaming SIM from OneSimCard
I run it in one or these, android, waterproof, rugged phone..
Amazon.com: FortisX V5 - IP67 Rugged Waterproof, Dustproof, Shockproof 3G Android 2.3 Smartphone Dual SIM 3.2"Touchscreen,5MP cacamera,GPS: Computers & Accessories
I will use it in Costa Rica and Panama this month.. so far it has worked pretty good. I have a 866 number linked to the one sim card that allows for my calls to get routed to me wherever I roam ..
HOLLYWOOD