A locked cell phone means that the phone is tied into one carrier and cannot be used on another company's network. You may want to unlock your phone if your cell phone provider's network has poor coverage in your area. All that's needed to check if your phone is locked or unlocked is another cell phone carrier's SIM card, which you can get from a friend or family member who uses a different cell phone company. CDMA phones, such as the Motorola Droid, do not have a SIM card and cannot be unlocked.
Look in your phone's user manual to see how to remove the SIM card. You can remove most SIM cards by simply sliding the card out of its compartment, beneath the battery. Turn your phone off before removing the SIM card.
Insert a SIM card from a different carrier into your phone. For example, if your phone was originally on the Verizon network, then slide an AT&T SIM card into your phone.
Turn on your phone. If your phone is locked, then you will receive an error message that says the phone is locked or cannot be used. Remove the SIM card and place the original SIM card back into your phone.