With the older iphones, the phone book was backed up every time you synced. The phone numbers are still accessible on the computer and you could even get vcards from it. Then, when you upgrade (like I did from 3GS to 4S) transferring numbers was a snap: just connect and hit sync.
Note that no phone numbers were stored on google's or apple's servers. A very significant portion of the iPhone crowd still sync via cable.
With the older iphones, the phone book was backed up every time you synced. The phone numbers are still accessible on the computer and you could even get vcards from it. Then, when you upgrade (like I did from 3GS to 4S) transferring numbers was a snap: just connect and hit sync.
Note that no phone numbers were stored on google's or apple's servers. A very significant portion of the iPhone crowd still sync via cable.