I have recently gotten a new Samsung Galaxy S II smartphone. I've never had one before. So, I'm trying to figure out how to use it so that I don't accidentally get charge for something not necessarily bad as much as like "accidentally banging your finger with a hammer". Right now, it appears to automatically access the Wi-Fi when it's in range and I'm installing free apps. Will I need to keep an eye on that so that it doesn't download apps (or additional app data) via a cell tower? (I did find a setting called "Wi-Fi Calling Settings" under which I can select Wi-Fi Prefered, Wi-Fi Only, Cellular Prefered.) There's, also, a gps on mine. I've found Google Maps, Google Latitude, Navigation, and TeleNav GPS Navigating that can use the gps in one way or another. How far into those programs can I use the gps before I start getting charged for data usage? Is there anything else I need to be careful of so that I don't end up surprised at the end of the billing cycle?