"Unlocked" applies to cell phones that can take any SIM card, also known as GSM cell phones. Carriers in the United States that use GSM technology are AT&T, Cingular, and T Mobile. Any of these unlocked phones will work with AT&T, Cingular, or T Mobile.
For those looking for a phone that will work in another country, many other countries use GSM technology exclusively, so these unlocked phones can be used both in the United States and elsewhere in the world. If you are looking for a phone guaranteed to work with any network in the world, we recommend the Motorola RAZR. It is a slim, sturdy phone with all the features that you need (Speakerphone, Bluetooth, Camera) and will work in almost any country.
