t-mobile charges about $3.99 a minut for roaming in colombia, Cingular is about a $1 cheaper, buth are way too expensive, thats why i have two cell phones, one for emergencies,USA phone. and an unlocked one from the USA with a comcel sim chip for local calls. best thing to do, is turn off your USA phone when in colombia, or any other country, turn it on, every once in a while, check to see if you got a voice mail, then turn it off and go call your phone from a Vonage line and listen to the voice mail, and if its an important call, call them back from the Vonage# chepaest way possible.