So what you guys are saying is that 1) if I use my BB for pretty much anything data-related I won't get charged -- regardless of which browser I use -- but once I use it like a modem on my laptop (say in a Starbucks where they gouge you at $9.99 a day) I will get charged?

I have the Blackberry unlimited data plan as well. I never heard anything about the Cingular browser being one that they charge you for.