iPhone 3GS jailbroken and unlocked. Ive never used a cell phone out of the country before and will be traveling to Canada next week for business and Greece later this summer for a vacation. I really only need a data plan but Id like to have a few minutes, just in case. What carriers are in Canada and Greece that have plans like this? Is it possible? Will the only thing I need to do is just swap out the SIM and Im good to go on the local network (and a new number of course)? Thanks in advance.