i have an iphone unlocked working with T-mobile and everything works fine but you will have to pay extra for the internet if its not already on your current plan. i use my wifi with free hot spots and in my home wireless system. the iphone can spoil you to the touch screen way of doing things and you know i like the ability to load whole internet pages. the down side to the current iphones is they don't support flash content such as imeem and most of youtube but youtube has switched a lot of their videos uploaded to mp4's so they work.
iphones are expensive .. I got a regular Unlocked TV phone from china ... can watch tv, add video, mp3, picture .. video recorder & sound recorder .. bluetooth capability and touchscreen .. and you can use it as a webcam also. As for the internet .. I'm still trying to figure out how to use it LoL ..