I was there about 10 months ago for adoption and never used my phone once. For calling back to the U.S. we just used Skype (via VPN). We stayed in 3 cities (all major cities) and each hotel we stayed in had 'net access in the rooms, either included as part of our package or for a fairly cheap rate. All photos were taken with our digital camera and just uploaded to our laptop at the end of each day. I didn't have any need for GPS data with the photos since I knew the towns we were in and places we were visiting thanks to an itinerary. You might not have that luxury.
I did bring my AT&T iPhone with me but left it in airplane mode the entire time. I really only used it as a wake-up alarm. I think I locked it in the room safe whenever we went out. I left it in my carry-on when flying and never had any problems with security.