using a blackberry out of country for an extended period of time

I currently live in the states and have a blackberry on AT&T but i'm planning on going up to live in canada for about two months and i was wondering if anyone knew if there was a way for me to still use my bb (i have an unlimited data plan) with all its features without paying roaming charges for two months. Is it possible to buy a canadian sim card that can allow me to make calls, sends SMS, and use data? I really know nothing about this kind of stuff so any information would be greatly appreciated. Thanks.

You can call AT&T and have them give you the unlock code so that you can use a canadian sim card. Or you can just use data while you're there.