i would think that if you dont have a data plan, then you cant do data stuff. it seems that the data part is a function of the service and not the device, so it should not matter if you try to do something that requires a data plan on the device, as your carrier is not providing you with a data connection.

think of it like this. take the ethernet cable out of your pc. you can open a browser, but you have no data connection, so you cannot get to the internet.