In its first month of release, the Apple iPhone 4S has only been available to those with wireless phone services from AT&T, Verizon Wireless and Sprint Nextel. As of now, versions of the new smartphone that contain no built-in micro-SIM card, generally referred to as "unlocked," are available from Apple's online store, according to Apple Insider.

The news source reports that these devices will only be useful to customers who have a GSM wireless service provider, such as AT&T in the U.S. and various carriers overseas. Those with Verizon, Sprint or other providers on CDMA networks will not be able to use unlocked versions of the phone.

Prices for unlocked devices will be equivalent to those for "locked" versions of the iPhone 4S purchased without a contract – $649 for the 16GB version, $749 for the 32GB and $849 for the 64GB. To buy one of the unlocked phones, customers must be 18 or older and be willing to subject themselves to a credit check, if Apple deems one necessary.

According to Mac Rumors, as of November 11, Sprint Nextel will be locking the micro-SIM card slot on the iPhone 4S units it provides, though this will apparently not affect those who have already purchased the device from Sprint.