Can I transfer my AT&T iPhone to the Verizon Network?
Nope. Unfortunately, some information found on Verizon's website has potentially confused some unhappy AT&T iPhone owners into thinking they can jump ship with their current iPhone and not have to buy a new iPhone for the Verizon network.
This isn't the case, you cannot use an AT&T compatible iPhone 4 on the Verizon Wireless network. Your current iPhone 4 in use on the AT&T network uses GSM / HSDPA technology and is not compatible with the Verizon Wireless network. The Verizon Wireless network compatible iPhone 4 is a 3G CDMA version of the iPhone 4.