Yes, It will depend on your provider. I was just reading yesterday that Verizon and T-Mobile have the best programs for BB to work Internationally.
Mooneydiva, Can't you get a SIM card from Sprint for it to work overseas? I don't understand all the inner workings, it's Greek to me. I know people that have had reception on mountain tops.
It's always best to just check with your provider and see if there's extra charges and if you need anything extra like the SIM.