Unlocked GSM Cell Phones (Global System for Mobile Communications) offer several advantages to consumers. Unlocked phones (phones not tied to a particular carrier) allow global travelers to stay in touch with their friends, family and work for a reasonable price. Before the advent of unlocked GSM phones, travelers were forced to use their US based cell phones and pay astronomical prices for any calls made and received overseas. Unlocked cell phones allow travelers to use SIM cards from the country they are visiting as well as Prepaid Global SIM Cards that may be used in numerous countries. There are several things that consumers must know before choosing the proper cell phone for their journey. There are four GSM networks used throughout the world. These networks are 850, 900, 1800, and 1900 Mhz. The exception is Japan and South Korea which does not use the GSM Network. In order for your phone to function in Japan you will need a phone that operates with 3G 2100 mhz (UMTS/HSDPA 2100 Mhz).Each country utilizes particular GSM networks. The GSM networks used by the SIM card must match those of the unlocked GSM cell phone types the customer chooses. The ideal is that you always carry a Quadband Unlocked GSM Cell Phone that would also supports 3G 850, 1900, and 2100 Mhz. These types of Unlocked Quadband GSM 3G Phones allows you to use your phone in all countries around the globe.While many US SIM cards support data usage, not all international SIM cards do. Further, your SIM card may support data usage, but may not be compatible with the operating system of the cell phone. Pangea Prepaid Global SIM Card is one the greatest Global SIM Cards that allows you to be connected in over 145 countries and offer free roaming (Free incoming calls) in more than 55 countries around the globe. The SIM Card offers Data in many countries as well. Pangea Global SIM Card is the only Dual IMSI SIM Card that allows you to have two numbers in your phone at the same time. If offers a local U.S. number and a U.K based local number within one SIM Card. There are also several advantages for GSM consumers in the United States in having an unlocked cell phone. One advantage is the freedom of using any GSM carrier you wish to use. Locked cell phones do not allow the use of any other GSM provider besides that of the carrier through whom you purchased the phone. Some cell phone providers may agree to unlock your GSM phone, but there is no guarantee. They may require that you have been under contract for a while with them, or agree to remain with them with some additional period of time. Cell phone providers are fearful that if your phone is unlocked you will switch to another carrier. Another advantage is that you may lend your phone to others or sell the phone. Further, you may have several cell phones to choose from at you leisure by simply inserting your SIM card. For example, you may not want to take your Apple iPhone on an outdoors trip. You can simply transfer your SIM card to a more rugged phone were a few scratches will not be the end of the world. Finally, consumers may purchase a prepaid SIM card from a US carrier that does not require a contract and use it in any unlocked GSM cell phone. Unlocked GSM cell phones have opened up a world where consumers are in control of their communication. No longer are consumers tied to one particular phone carrier and one particular phone. At a time when consumers are watching every penny there is no contract with a monthly bill due and no huge phone bill for using one’s cell phone overseas.