The Verizon phone uses CDMA so there is nowhere to put a GSM SIM. But a bit of hacking allowed him to add a SIM card slot to it. Even though he’s not the one who originally found this hack (XDA ...
This allows for a seamless interchange of the same SIM card between different GSM mobile phones. SIM cards also serve as storage for SMS messages and the user's contacts. Current SIM cards can ...