I know the VZW and Sprint versions require a data plan. But the "unlocked" version that you buy from the Google Play store, can it be used without hooking it up to a carrier and activated with home Wi-Fi? Basically in the future when the unlimited data plans disappear looking to have a cell phone but don't really have a need for mobile data other then when at wifi spots. Esp with google maps going offline. Since it is unlocked why would you need to be tied to a carriers data plan? If not is there a pay as you go data sim that could be used to activate and then be disabled?