dbltap brought up a few good points that I should clarify. First, I am on AT&T, but unlike dbltp, I am using the Blackberry International with Voice Plan (not the the International Data Plan for Smartphones, PDAs and iPhones). They are much different in their coverage. The Int'l PDA/Smartphone plan is, as mentioned, only valid in 85 countries with (apparently) select providers. The BB Int'l Plan DOES require a 1 year commitment, but works in "over 150 countries". In my experience, if I have a signal, I'm covered, no extra charges. For any data I use on my BB (email, web, etc).
The details from AT&T:
"BlackBerry International with Voice $64.99 per month
Combine BlackBerry International with your existing wireless voice plan and get a $5 monthly discount off the $69.99 data plan price.
Call 1-800-331-0500 to sign up now.
One–year minimum term required for this plan."
MY NOTE: The $65/$69 is the total for the BB data, whether in the US or outside (it replaces the "in the US-only" BB data plan you probably already have).
Hope that helps. Just make sure you get the right plan for your needs. If you need more, let me know.
dbltap, I hate to ask much AT&T got you for for extra data charges. Sounds like the original iPhone roaming $1000 bills...