Call VZW and tell them to activate your GSM card and get the Global Data Plan. They will take off the normal BB plan, so it should only be about $20 more per month (you can cancel when you come back and have it pro-rated). I'm in Thailand and did this and it works great. You can use any programs that use data, plus you get all your e-mail. You still have to pay roaming for phone calls and for text messages though. But if all you want is data (which is all I was looking for as well), this works perfectly.
yeah - get the global data plan, but do whatever you can to stay off the phone (making/receiving calls, checking v-mail) - the roaming charges are ridiculous.