I have a similar situation - my wife just upgraded and so we have a spare phone (Sprint/Samsung Epic 4G) that we'd like to let the kids use for games, videos, etc.
I want to ensure the kids (both under 10) cannot make calls, send texts, etc. But using games/wifi/internet/youtube will be fine since we do supervise them.
Is there anything I can/should do to lock down the cellular connectivity of the phone? Or is it incapable of making calls since Sprint activated my wife's same phone number on a new phone?