IPhone 3G SIM card, Deactivating it?

[#1MustangFan]

Just take the SIM card out of it and do a master reset on the device and all of your info will be gone. If you are still keeping AT&T service then just put the SIM in another device. If you are cancelling your service then the SIM will automatically be deactivated in that process.

Master reset: Settings>General>Reset>Erase All Content and Settings. This will wipe the device of all content and reset it to factory settings

 

[ThomasF]

Im ready to sell my IPhone 3G on ebay. If i deactivate my SIM card will they have the same number? Possibly even find my contacts or any of my information( Name, Birthday, Ect)?