Call global support, choose the option for global email program. You get a person right away. Tell them where you're traveling, and that you want to activate your sim card and activate the global email feature. Two options, $65 / month is unlimited data and no special price on calling, $70 / month is unlimited data and a slight discount on calling. Which one depends on how much calling you will do. I do no calling, only data, so I opt for the $65 plan.
Unless you're going to use foreign service with a different sim card (which will require unlocking the phone with an unlock code from the same global services folks, just ask for the code), use the global plan, don't roam. Roaming charges are insane, simple use over the course of a few days will rack up a several hundred dollar bill. I've learned this because of glitches in their system that sent me messages that I had racked up such a bill, but upon calling them, they assured me it was a glitch and I was on the unlimited plan. Wouldn't want to be roaming!
When you come back from overseas, wait a day, especially if you're coming back from the far east (crossing the international dateline heading east) and then call global services, asking to discontinue the global plan. They will revert you back to the domestic $30 / month plan and your bill will be prorated for the portion of the month you were overseas. It works great, you can turn it off and on as often as you like, and you have unlimited data overseas.
