It may not be possible depending on how old it is. If it is what we call an "old blue" AT&T device, one that was made before the merger with Cingular, then you probably will not be able to. You can call Customer Service at 1-800-331-0500 and they will be able to advise you for sure if it is possible or not. If it is able to be unlocked then they will be able to help you with that also at that number.
If the phone is from the same carrier then yes, it is very simple. If you were to try and put, for example, a T-Mobile SIM into a Cingular phone or vice versa, you will need to "Unlock the phone" first.
If you want to switch carriers or use your Motorola i365 overseas, you will have to unlock the phone. Turn off the phone and open the back. Remove the battery and SIM card. Write down the International Mobile Equipment Identification (IMEI) number located on the bottom of the battery. Insert the new provider's SIM card, replace the phone's battery and back cover. Call your old carrier, provide the IMEI number and they will give you the unlock code. Turn on the phone and enter the unlock code. Your phone will restart and the new network information will be displayed.
You save all of your numbers to your sim card on your old phone then put your sim card in your new phone. Simple. :D
Put the SIM card from the new phone into the old one. Copy the contacts from the old phone's memory to the SIM card. Put the SIM car back in the new phone - then - either copy the contacts to the new phone's memory - or leave them on the SIM card. Either way - the new phone will find them.
you have to put YOUR sim card in. from your old phone.
When you buy a tmobile phone it camoes with a sim card. If you already have a tmobile phone and break it you can buy a pre-paid phone and put your old sim card in it
No. You have to transfer the data.
yes
full form of sms
No reason why not - the old SIM card should still work.
The old SIM card will still be programmed with the original phone number. Either SIM will work in the phone - unless the old SIM is blocked by the network when they issued the new one.
In your old Virgin phone - copy everything you want to keep (contacts, pictures etc) from the memory to the SIM card. Put the SIM card in the new phone, then copy everything from the SIM card to the new phone's memory. Once you've done that - replace the old SIM with the one that came with your new phone.