Any cellular phone unit can be used for GPS purposes as long it has all the necessary requirements that makes a GPS phone. First important component is the GPS receiver. There are 24 satellites orbitting the earth today. These satellites send signals that the GPS receiver can receive and process. If it happens that there is no GPS receiver to your cellular phone, you can easily connect it to a GPS receiver by using serial or USB port or even the Bluetooth trace cell phone numbers. Second thing to consider is the cellular phone network company that provides the services to your line. You usually have to first get a special plan that will let you utilize the GPS service. Sometimes, this could even require you to avail of a data service.