Hello,
Is it possible to use verizon iPhone 4s on AT&T's network with Gevey sim unlock? I tried, but can't seem to find how to active it. Any help appreciated.
AT&T and Verizon use two different cell phone technologies (GSM vs. CDMA). They are entirely incompatible with each other.
In other words no, it is not possible to use a Verizon phone on AT&T.
Well i dont know where you got your info but your wrong. You can use the Gevey Ultra S Sim for Sprint/Verizon iPhone 4s and if you use that you would be able to unlock it and use it on whichever GSM carrier that you may desire.