Pay-as-you-go cell phone provider Straight Talk employs SIM cards, allowing you to use your own unlocked GSM or CDMA phone on the network or purchase one of the phones that the company offers directly ...

So you are looking for the best smartphones with Nano SIM card slots? Well, let’s get into it then. Those of you who are not familiar with SIM cards, I bet you use CDMA phones. SIM (subscriber ...

Some owners of Apple's new iPhone 4S have been hit with SIM card error messages, even if they are connected to a CDMA carrier that does not use SIM cards. One reader ...

Activate a cellphone that is currently inactive to begin using service on the device. Two types of cellphone technology exist: CDMA, or phone that don't use SIM cards; and GSM phones that do. The ...

Does Sprint even offer GSM service? If not, I don't see how your Razr would work. The Sanyo is a CDMA phone. IIRC, only Cingular and T-Mobile offer GSM service in the US.